Keith B. Holten, MD

An extensive and expensive evaluation for irritable bowel syndrome (IBS) can be avoided if your patient is aged <50 years and is not experiencing alarm symptoms (hematochezia, 10 lbs weight loss, fever, anemia, nocturnal or severe diarrhea), has not recently taken antibiotics, and has no family history of colon cancer. An algorithm ( Figure ) indicates when work-up is needed and what it should entail.

Newer medications that act on 5HT receptors have proven effective in improving quality of life (global symptom reduction). Evidence supports the use of several traditional medications to reduce individual symptoms of IBS, but not for global symptom reduction.

FIGURE
Evaluating possible irritable bowel syndrome

Who gets irritable bowel syndrome?

Ten percent to 15% of the North American population has IBS, and twice as many women as men have it.¹ Symptoms usually begin before the age of 35 years, and many patients can trace their symptoms back to childhood.² Onset in the elderly is rare.³ The disorder is responsible for approximately 50% of referrals to gastroenterologists.⁴

The company IBS keeps

Comorbid psychiatric illness is common with IBS, but few patients seek psychiatric care.⁵ Depression, anxiety, and somatoform disorders are seen in 94% of patients with IBS. IBS is common in patients with chronic fatigue syndrome (51%), fibromyalgia (49%), temporomandibular joint syndrome (64%), and chronic pelvic pain (50%).⁶ IBS often follows stressful life events,^5,7,8 such as a death in the family or divorce. It tends to be chronic, intermittent, and relapsing.³

The symptoms of IBS can overlap with those of other illnesses, including thyroid dysfunction (diarrhea or constipation), functional dyspepsia (abdominal pain), Crohn’s disease or ulcerative colitis (diarrhea, abdominal pain), celiac sprue (diarrhea), polyps and cancers (constipation or abdominal pain), and infectious diarrhea.

Elusive physiologic mechanism

Several physiologic mechanisms have been proposed for IBS symptoms: altered gut reactivity in response to luminal stimuli, hypersensitive gut with enhanced pain response, and altered brain-gut biochemical axis.⁹ Though the symptoms of irritable bowel syndrome appear to have a physiologic basis, there are no structural or biochemical markers for the disease.

Use symptom-based criteria for diagnosis

Consider a diagnosis of IBS when a patient complains of abdominal discomfort and altered bowel habits. In the absence of a structural or biochemical marker, IBS must be diagnosed according to symptom-based criteria–such as Manning, Rome I, or Rome II–which have been developed for research and epidemiologic purposes. Though their clinical utility remains unproven, these criteria (delineated in Table 1 ) are the crux of clinical diagnosis for IBS.^4,10-14 Subtypes of IBS have been described (diarrheapredominant IBS or constipation-predominant IBS), but they are not diagnostically useful, since the treatment goal is improved quality of life.

TABLE 1
Symptom-based criteria for irritable bowel syndrome

Dubious value of diagnostic tests

The literature regarding the value of diagnostic testing for IBS is controversial. Symptom-based criteria have varied in many studies, as have the criteria used to enroll patients and the measured outcomes of treatment (reduction in abdominal pain, in diarrhea, or in constipation, or improvement in quality of life). Because of these discrepancies, it is difficult to apply the literature clinically. Of the 6 landmark studies that considered the value of diagnostic testing for IBS patients,^15-20 only 2 compared IBS patients with groups of healthy controls.^17,19

Test results yield little. Most research in this area has compared the prevalence of specific illnesses in the general population with the yield of positive test results for these illnesses among persons meeting the symptom-based diagnostic criteria for IBS.

Two studies^15,16 determined the incidence of abnormal test results in patients who met the Manning or Rome I criteria for IBS. In these studies, most diagnostic tests yielded positive results in 2% (range, 0%-8.2%) of patients or less, except for thyroid and lactose intolerance testing. That is equivalent to the incidence in the general population. The prevalence of thyroid disorders and lactose malabsorption was higher in IBS patients (6% and 22%-26%, respectively), but prevalence in the general population is similarly higher (5%-9% and 25%). Based on these results, testing for thyroid disease or lactose malabsorption is indicated only for patients exhibiting symptoms of these disorders (fatigue/weight change or diarrhea related to diertary intake of dairy products, respectively).

An exception. Some clinicians propose that diagnostic testing for patients with IBS symptoms should be driven by the pretest probability of organic disease (prevalence) compared with the general population. Cash²¹ found the pretest probability of inflammatory bowel disease, colorectal cancer, and infectious diarrhea is less than 1% among IBS patients without alarm symptoms ( Table 2 ). He demonstrated that patients with IBS had a 5% pretest probability of celiac sprue compared with healthy patients (<1% prevalence). Therefore, testing for celiac sprue (eg, complete blood count, antiendomysial antibody, and antigliadin antibody) may be considered for patients with diarrhea.^6,21,22 Sigmoidoscopy,^15,17 rectal biopsy,¹⁷ and abdominal ultrasound¹⁸ have low positive yield in patients meeting the diagnostic criteria for IBS.

TABLE 2
Probability of organic disease in irritable bowel syndrome patients

How to proceed

Those under 50 years of age who have no alarm symptoms can forgo further testing. Testing for celiac sprue and lactose malabsorption might be considered for patients with diarrhea that improves or worsens with change in diet (strength of recommendation [SOR]: C).

Threshold for treatment

Treatment for IBS is indicated when both patient and physician believe global symptoms (abdominal discomfort, bloating, altered bowel habits) have diminished the quality of life (SOR: C). The goal of treatment is to alleviate all IBS symptoms (SOR: C). Treating altered bowel habits (constipation, diarrhea, and fecal urgency) without addressing other IBS symptoms (eg, abdominal pain) is inferior treatment.^23,24

Treatment options for IBS

Treatments for IBS include medications, behavior therapy, and complimentary and alternative therapies. Medications traditionally prescribed include bulking agents, anticholinergics/antispasmodics, antidiarrheals, and antidepressants. A 5HT₃ receptor antagonist and a 5HT₄ receptor partial agonist are now available. Table 3 summarizes the traditional treatments in terms of efficacy, strength of recommendations, and outcomes measured. Alternative and complimentary therapies appear in Table 4 .

As Brandt²⁴ has noted, the evidence for treatment effectiveness is difficult to review and summarize, because the quality of studies has been poor. Most studies did not use healthy control groups, and the numbers of participants were small. Many studies did not use blinded placebo groups. Outcomes measured varied among the studies, with most of them measuring reductions of individual bowel symptoms (eg, diarrhea or constipation). Quality-of-life tools were used in other studies to measure reduction in global IBS symptoms (eg, IBS Quality of Life ²⁵ ). Because of these discrepancies, there is no sound evidence for traditional therapies.

TABLE 3
Treatments for irritable bowel syndrome

TABLE 4
Complementary and alternative treatments for irritable bowel syndrome

Medications

Strength of recommendation: A. The recently approved 5HT₄ receptor agonist tegaserod (Zelnorm) is more effective than placebo at relieving global symptoms in women with constipation (number needed to treat [NNT]=3.9-17).^26-30 Diarrhea can be a serious side effect.

The 5HT₃ receptor antagonist alosetron (Lotronex) is more effective than placebo at relieving global IBS symptoms in women with diarrhea (NNT=2.5-8.3).^31-35 Severe constipation can be an adverse effect. The prescribing of alosetron is currently restricted to physicians who participate in the manufacturer’s risk management program.

In addition to these serotoninergic agents, others in this class are being developed and undergoing clinical trials. The knowledge being gained about 5HT receptors may revolutionize the care of patients with IBS.

Strength of recommendation: B. Tricyclic antidepressants are no more effective than placebo at relieving global IBS symptoms, but they do decrease abdominal pain (NNT=3.2-5).^36-39

Loperamide is no more effective than placebo at relieving IBS global symptoms, but it may be used to treat diarrhea (NNT=2.3-5).^31,40-42

Bulking agents (such as calcium polycarbophil or psyllium) are no more effective than placebo at relieving IBS global symptoms, but they may decrease constipation (NNT=2.2-8.6).^31,36,43-47

Peppermint oil may be helpful for abdominal pain, but global symptom reduction has not been demonstrated.^31,48-49 Only a few studies have looked at the use of antispasmodic agents for IBS. They are of poor quality and used small numbers with no placebo controls.^23,31,36,43

Strength of recommendation: C. There are limited studies evaluating the selective serotonin reuptake inhibitors (SSRIs) fluoxetine and paroxetine. Paroxetine was shown in 1 study to improve quality of life.⁵⁰ Fluoxetine reduced abdominal pain, but did not improve quality of life.⁵¹

Behavioral and complementary/alternative therapies

Relaxation therapy, hypnotherapy, and cognitive therapy are effective at relieving individual IBS symptoms, but have not been shown to reduce global IBS symptoms (SOR: B).^52-57 Other alternative therapies (eg, guar gum⁴⁴ [SOR: B], ginger⁴⁸ [SOR: B], and pancreatic enzymes⁴⁸ [SOR: C]) have been studied, but high-quality studies considering global improvement have not been published.

Promote self-awareness

Quality-of-life assessment should be done routinely in the care of IBS patients. Provide support, empathy, and basic behavior modification tools. Educate patients and their families on the theoretical biochemical basis of this illness, and help them connect symptoms with stressors, to facilitate lifestyle modification.

Correspondence
Keith B. Holten, MD, Clinton Memorial Hospital/University of Cincinnati Family Practice Residency, 825 W. Locust St., Wilmington, OH, 45177. E-mail: [email protected].

An extensive and expensive evaluation for irritable bowel syndrome (IBS) can be avoided if your patient is aged <50 years and is not experiencing alarm symptoms (hematochezia, 10 lbs weight loss, fever, anemia, nocturnal or severe diarrhea), has not recently taken antibiotics, and has no family history of colon cancer. An algorithm ( Figure ) indicates when work-up is needed and what it should entail.

Newer medications that act on 5HT receptors have proven effective in improving quality of life (global symptom reduction). Evidence supports the use of several traditional medications to reduce individual symptoms of IBS, but not for global symptom reduction.

FIGURE
Evaluating possible irritable bowel syndrome

Who gets irritable bowel syndrome?

Ten percent to 15% of the North American population has IBS, and twice as many women as men have it.¹ Symptoms usually begin before the age of 35 years, and many patients can trace their symptoms back to childhood.² Onset in the elderly is rare.³ The disorder is responsible for approximately 50% of referrals to gastroenterologists.⁴

The company IBS keeps

Comorbid psychiatric illness is common with IBS, but few patients seek psychiatric care.⁵ Depression, anxiety, and somatoform disorders are seen in 94% of patients with IBS. IBS is common in patients with chronic fatigue syndrome (51%), fibromyalgia (49%), temporomandibular joint syndrome (64%), and chronic pelvic pain (50%).⁶ IBS often follows stressful life events,^5,7,8 such as a death in the family or divorce. It tends to be chronic, intermittent, and relapsing.³

The symptoms of IBS can overlap with those of other illnesses, including thyroid dysfunction (diarrhea or constipation), functional dyspepsia (abdominal pain), Crohn’s disease or ulcerative colitis (diarrhea, abdominal pain), celiac sprue (diarrhea), polyps and cancers (constipation or abdominal pain), and infectious diarrhea.

Elusive physiologic mechanism

Several physiologic mechanisms have been proposed for IBS symptoms: altered gut reactivity in response to luminal stimuli, hypersensitive gut with enhanced pain response, and altered brain-gut biochemical axis.⁹ Though the symptoms of irritable bowel syndrome appear to have a physiologic basis, there are no structural or biochemical markers for the disease.

Use symptom-based criteria for diagnosis

Consider a diagnosis of IBS when a patient complains of abdominal discomfort and altered bowel habits. In the absence of a structural or biochemical marker, IBS must be diagnosed according to symptom-based criteria–such as Manning, Rome I, or Rome II–which have been developed for research and epidemiologic purposes. Though their clinical utility remains unproven, these criteria (delineated in Table 1 ) are the crux of clinical diagnosis for IBS.^4,10-14 Subtypes of IBS have been described (diarrheapredominant IBS or constipation-predominant IBS), but they are not diagnostically useful, since the treatment goal is improved quality of life.

TABLE 1
Symptom-based criteria for irritable bowel syndrome

Dubious value of diagnostic tests

The literature regarding the value of diagnostic testing for IBS is controversial. Symptom-based criteria have varied in many studies, as have the criteria used to enroll patients and the measured outcomes of treatment (reduction in abdominal pain, in diarrhea, or in constipation, or improvement in quality of life). Because of these discrepancies, it is difficult to apply the literature clinically. Of the 6 landmark studies that considered the value of diagnostic testing for IBS patients,^15-20 only 2 compared IBS patients with groups of healthy controls.^17,19

Test results yield little. Most research in this area has compared the prevalence of specific illnesses in the general population with the yield of positive test results for these illnesses among persons meeting the symptom-based diagnostic criteria for IBS.

Two studies^15,16 determined the incidence of abnormal test results in patients who met the Manning or Rome I criteria for IBS. In these studies, most diagnostic tests yielded positive results in 2% (range, 0%-8.2%) of patients or less, except for thyroid and lactose intolerance testing. That is equivalent to the incidence in the general population. The prevalence of thyroid disorders and lactose malabsorption was higher in IBS patients (6% and 22%-26%, respectively), but prevalence in the general population is similarly higher (5%-9% and 25%). Based on these results, testing for thyroid disease or lactose malabsorption is indicated only for patients exhibiting symptoms of these disorders (fatigue/weight change or diarrhea related to diertary intake of dairy products, respectively).

An exception. Some clinicians propose that diagnostic testing for patients with IBS symptoms should be driven by the pretest probability of organic disease (prevalence) compared with the general population. Cash²¹ found the pretest probability of inflammatory bowel disease, colorectal cancer, and infectious diarrhea is less than 1% among IBS patients without alarm symptoms ( Table 2 ). He demonstrated that patients with IBS had a 5% pretest probability of celiac sprue compared with healthy patients (<1% prevalence). Therefore, testing for celiac sprue (eg, complete blood count, antiendomysial antibody, and antigliadin antibody) may be considered for patients with diarrhea.^6,21,22 Sigmoidoscopy,^15,17 rectal biopsy,¹⁷ and abdominal ultrasound¹⁸ have low positive yield in patients meeting the diagnostic criteria for IBS.

TABLE 2
Probability of organic disease in irritable bowel syndrome patients

How to proceed

Those under 50 years of age who have no alarm symptoms can forgo further testing. Testing for celiac sprue and lactose malabsorption might be considered for patients with diarrhea that improves or worsens with change in diet (strength of recommendation [SOR]: C).

Threshold for treatment

Treatment for IBS is indicated when both patient and physician believe global symptoms (abdominal discomfort, bloating, altered bowel habits) have diminished the quality of life (SOR: C). The goal of treatment is to alleviate all IBS symptoms (SOR: C). Treating altered bowel habits (constipation, diarrhea, and fecal urgency) without addressing other IBS symptoms (eg, abdominal pain) is inferior treatment.^23,24

Treatment options for IBS

Treatments for IBS include medications, behavior therapy, and complimentary and alternative therapies. Medications traditionally prescribed include bulking agents, anticholinergics/antispasmodics, antidiarrheals, and antidepressants. A 5HT₃ receptor antagonist and a 5HT₄ receptor partial agonist are now available. Table 3 summarizes the traditional treatments in terms of efficacy, strength of recommendations, and outcomes measured. Alternative and complimentary therapies appear in Table 4 .

As Brandt²⁴ has noted, the evidence for treatment effectiveness is difficult to review and summarize, because the quality of studies has been poor. Most studies did not use healthy control groups, and the numbers of participants were small. Many studies did not use blinded placebo groups. Outcomes measured varied among the studies, with most of them measuring reductions of individual bowel symptoms (eg, diarrhea or constipation). Quality-of-life tools were used in other studies to measure reduction in global IBS symptoms (eg, IBS Quality of Life ²⁵ ). Because of these discrepancies, there is no sound evidence for traditional therapies.

TABLE 3
Treatments for irritable bowel syndrome

TABLE 4
Complementary and alternative treatments for irritable bowel syndrome

Medications

Strength of recommendation: A. The recently approved 5HT₄ receptor agonist tegaserod (Zelnorm) is more effective than placebo at relieving global symptoms in women with constipation (number needed to treat [NNT]=3.9-17).^26-30 Diarrhea can be a serious side effect.

The 5HT₃ receptor antagonist alosetron (Lotronex) is more effective than placebo at relieving global IBS symptoms in women with diarrhea (NNT=2.5-8.3).^31-35 Severe constipation can be an adverse effect. The prescribing of alosetron is currently restricted to physicians who participate in the manufacturer’s risk management program.

In addition to these serotoninergic agents, others in this class are being developed and undergoing clinical trials. The knowledge being gained about 5HT receptors may revolutionize the care of patients with IBS.

Strength of recommendation: B. Tricyclic antidepressants are no more effective than placebo at relieving global IBS symptoms, but they do decrease abdominal pain (NNT=3.2-5).^36-39

Loperamide is no more effective than placebo at relieving IBS global symptoms, but it may be used to treat diarrhea (NNT=2.3-5).^31,40-42

Bulking agents (such as calcium polycarbophil or psyllium) are no more effective than placebo at relieving IBS global symptoms, but they may decrease constipation (NNT=2.2-8.6).^31,36,43-47

Peppermint oil may be helpful for abdominal pain, but global symptom reduction has not been demonstrated.^31,48-49 Only a few studies have looked at the use of antispasmodic agents for IBS. They are of poor quality and used small numbers with no placebo controls.^23,31,36,43

Strength of recommendation: C. There are limited studies evaluating the selective serotonin reuptake inhibitors (SSRIs) fluoxetine and paroxetine. Paroxetine was shown in 1 study to improve quality of life.⁵⁰ Fluoxetine reduced abdominal pain, but did not improve quality of life.⁵¹

Behavioral and complementary/alternative therapies

Relaxation therapy, hypnotherapy, and cognitive therapy are effective at relieving individual IBS symptoms, but have not been shown to reduce global IBS symptoms (SOR: B).^52-57 Other alternative therapies (eg, guar gum⁴⁴ [SOR: B], ginger⁴⁸ [SOR: B], and pancreatic enzymes⁴⁸ [SOR: C]) have been studied, but high-quality studies considering global improvement have not been published.

Promote self-awareness

Quality-of-life assessment should be done routinely in the care of IBS patients. Provide support, empathy, and basic behavior modification tools. Educate patients and their families on the theoretical biochemical basis of this illness, and help them connect symptoms with stressors, to facilitate lifestyle modification.

Correspondence
Keith B. Holten, MD, Clinton Memorial Hospital/University of Cincinnati Family Practice Residency, 825 W. Locust St., Wilmington, OH, 45177. E-mail: [email protected].

An extensive and expensive evaluation for irritable bowel syndrome (IBS) can be avoided if your patient is aged <50 years and is not experiencing alarm symptoms (hematochezia, 10 lbs weight loss, fever, anemia, nocturnal or severe diarrhea), has not recently taken antibiotics, and has no family history of colon cancer. An algorithm ( Figure ) indicates when work-up is needed and what it should entail.

Newer medications that act on 5HT receptors have proven effective in improving quality of life (global symptom reduction). Evidence supports the use of several traditional medications to reduce individual symptoms of IBS, but not for global symptom reduction.

FIGURE
Evaluating possible irritable bowel syndrome

Who gets irritable bowel syndrome?

Ten percent to 15% of the North American population has IBS, and twice as many women as men have it.¹ Symptoms usually begin before the age of 35 years, and many patients can trace their symptoms back to childhood.² Onset in the elderly is rare.³ The disorder is responsible for approximately 50% of referrals to gastroenterologists.⁴

The company IBS keeps

Comorbid psychiatric illness is common with IBS, but few patients seek psychiatric care.⁵ Depression, anxiety, and somatoform disorders are seen in 94% of patients with IBS. IBS is common in patients with chronic fatigue syndrome (51%), fibromyalgia (49%), temporomandibular joint syndrome (64%), and chronic pelvic pain (50%).⁶ IBS often follows stressful life events,^5,7,8 such as a death in the family or divorce. It tends to be chronic, intermittent, and relapsing.³

The symptoms of IBS can overlap with those of other illnesses, including thyroid dysfunction (diarrhea or constipation), functional dyspepsia (abdominal pain), Crohn’s disease or ulcerative colitis (diarrhea, abdominal pain), celiac sprue (diarrhea), polyps and cancers (constipation or abdominal pain), and infectious diarrhea.

Elusive physiologic mechanism

Several physiologic mechanisms have been proposed for IBS symptoms: altered gut reactivity in response to luminal stimuli, hypersensitive gut with enhanced pain response, and altered brain-gut biochemical axis.⁹ Though the symptoms of irritable bowel syndrome appear to have a physiologic basis, there are no structural or biochemical markers for the disease.

Use symptom-based criteria for diagnosis

Consider a diagnosis of IBS when a patient complains of abdominal discomfort and altered bowel habits. In the absence of a structural or biochemical marker, IBS must be diagnosed according to symptom-based criteria–such as Manning, Rome I, or Rome II–which have been developed for research and epidemiologic purposes. Though their clinical utility remains unproven, these criteria (delineated in Table 1 ) are the crux of clinical diagnosis for IBS.^4,10-14 Subtypes of IBS have been described (diarrheapredominant IBS or constipation-predominant IBS), but they are not diagnostically useful, since the treatment goal is improved quality of life.

TABLE 1
Symptom-based criteria for irritable bowel syndrome

Dubious value of diagnostic tests

The literature regarding the value of diagnostic testing for IBS is controversial. Symptom-based criteria have varied in many studies, as have the criteria used to enroll patients and the measured outcomes of treatment (reduction in abdominal pain, in diarrhea, or in constipation, or improvement in quality of life). Because of these discrepancies, it is difficult to apply the literature clinically. Of the 6 landmark studies that considered the value of diagnostic testing for IBS patients,^15-20 only 2 compared IBS patients with groups of healthy controls.^17,19

Test results yield little. Most research in this area has compared the prevalence of specific illnesses in the general population with the yield of positive test results for these illnesses among persons meeting the symptom-based diagnostic criteria for IBS.

Two studies^15,16 determined the incidence of abnormal test results in patients who met the Manning or Rome I criteria for IBS. In these studies, most diagnostic tests yielded positive results in 2% (range, 0%-8.2%) of patients or less, except for thyroid and lactose intolerance testing. That is equivalent to the incidence in the general population. The prevalence of thyroid disorders and lactose malabsorption was higher in IBS patients (6% and 22%-26%, respectively), but prevalence in the general population is similarly higher (5%-9% and 25%). Based on these results, testing for thyroid disease or lactose malabsorption is indicated only for patients exhibiting symptoms of these disorders (fatigue/weight change or diarrhea related to diertary intake of dairy products, respectively).

An exception. Some clinicians propose that diagnostic testing for patients with IBS symptoms should be driven by the pretest probability of organic disease (prevalence) compared with the general population. Cash²¹ found the pretest probability of inflammatory bowel disease, colorectal cancer, and infectious diarrhea is less than 1% among IBS patients without alarm symptoms ( Table 2 ). He demonstrated that patients with IBS had a 5% pretest probability of celiac sprue compared with healthy patients (<1% prevalence). Therefore, testing for celiac sprue (eg, complete blood count, antiendomysial antibody, and antigliadin antibody) may be considered for patients with diarrhea.^6,21,22 Sigmoidoscopy,^15,17 rectal biopsy,¹⁷ and abdominal ultrasound¹⁸ have low positive yield in patients meeting the diagnostic criteria for IBS.

TABLE 2
Probability of organic disease in irritable bowel syndrome patients

How to proceed

Those under 50 years of age who have no alarm symptoms can forgo further testing. Testing for celiac sprue and lactose malabsorption might be considered for patients with diarrhea that improves or worsens with change in diet (strength of recommendation [SOR]: C).

Threshold for treatment

Treatment for IBS is indicated when both patient and physician believe global symptoms (abdominal discomfort, bloating, altered bowel habits) have diminished the quality of life (SOR: C). The goal of treatment is to alleviate all IBS symptoms (SOR: C). Treating altered bowel habits (constipation, diarrhea, and fecal urgency) without addressing other IBS symptoms (eg, abdominal pain) is inferior treatment.^23,24

Treatment options for IBS

Treatments for IBS include medications, behavior therapy, and complimentary and alternative therapies. Medications traditionally prescribed include bulking agents, anticholinergics/antispasmodics, antidiarrheals, and antidepressants. A 5HT₃ receptor antagonist and a 5HT₄ receptor partial agonist are now available. Table 3 summarizes the traditional treatments in terms of efficacy, strength of recommendations, and outcomes measured. Alternative and complimentary therapies appear in Table 4 .

As Brandt²⁴ has noted, the evidence for treatment effectiveness is difficult to review and summarize, because the quality of studies has been poor. Most studies did not use healthy control groups, and the numbers of participants were small. Many studies did not use blinded placebo groups. Outcomes measured varied among the studies, with most of them measuring reductions of individual bowel symptoms (eg, diarrhea or constipation). Quality-of-life tools were used in other studies to measure reduction in global IBS symptoms (eg, IBS Quality of Life ²⁵ ). Because of these discrepancies, there is no sound evidence for traditional therapies.

TABLE 3
Treatments for irritable bowel syndrome

TABLE 4
Complementary and alternative treatments for irritable bowel syndrome

Medications

Strength of recommendation: A. The recently approved 5HT₄ receptor agonist tegaserod (Zelnorm) is more effective than placebo at relieving global symptoms in women with constipation (number needed to treat [NNT]=3.9-17).^26-30 Diarrhea can be a serious side effect.

The 5HT₃ receptor antagonist alosetron (Lotronex) is more effective than placebo at relieving global IBS symptoms in women with diarrhea (NNT=2.5-8.3).^31-35 Severe constipation can be an adverse effect. The prescribing of alosetron is currently restricted to physicians who participate in the manufacturer’s risk management program.

In addition to these serotoninergic agents, others in this class are being developed and undergoing clinical trials. The knowledge being gained about 5HT receptors may revolutionize the care of patients with IBS.

Strength of recommendation: B. Tricyclic antidepressants are no more effective than placebo at relieving global IBS symptoms, but they do decrease abdominal pain (NNT=3.2-5).^36-39

Loperamide is no more effective than placebo at relieving IBS global symptoms, but it may be used to treat diarrhea (NNT=2.3-5).^31,40-42

Bulking agents (such as calcium polycarbophil or psyllium) are no more effective than placebo at relieving IBS global symptoms, but they may decrease constipation (NNT=2.2-8.6).^31,36,43-47

Peppermint oil may be helpful for abdominal pain, but global symptom reduction has not been demonstrated.^31,48-49 Only a few studies have looked at the use of antispasmodic agents for IBS. They are of poor quality and used small numbers with no placebo controls.^23,31,36,43

Strength of recommendation: C. There are limited studies evaluating the selective serotonin reuptake inhibitors (SSRIs) fluoxetine and paroxetine. Paroxetine was shown in 1 study to improve quality of life.⁵⁰ Fluoxetine reduced abdominal pain, but did not improve quality of life.⁵¹

Behavioral and complementary/alternative therapies

Relaxation therapy, hypnotherapy, and cognitive therapy are effective at relieving individual IBS symptoms, but have not been shown to reduce global IBS symptoms (SOR: B).^52-57 Other alternative therapies (eg, guar gum⁴⁴ [SOR: B], ginger⁴⁸ [SOR: B], and pancreatic enzymes⁴⁸ [SOR: C]) have been studied, but high-quality studies considering global improvement have not been published.

Promote self-awareness

Quality-of-life assessment should be done routinely in the care of IBS patients. Provide support, empathy, and basic behavior modification tools. Educate patients and their families on the theoretical biochemical basis of this illness, and help them connect symptoms with stressors, to facilitate lifestyle modification.

Correspondence
Keith B. Holten, MD, Clinton Memorial Hospital/University of Cincinnati Family Practice Residency, 825 W. Locust St., Wilmington, OH, 45177. E-mail: [email protected].

Psychiatrists often treat patients with irritable bowel syndrome (IBS) and an accompanying mental illness. Knowledge of available treatments and communication with the referring doctor are crucial to treating both the IBS symptoms and the comorbidity.

This article presents three cases that illustrate the challenges of identifying target symptoms, avoiding drug-drug interactions, ruling out serious underlying medical problems, and formulating treatment.

WHO GETS IBS?

Approximately 12% of the United States population reports IBS symptoms (abdominal pain, bloating, altered bowel habits).¹ These symptoms begin before age 35 in most patients and during childhood in some. Onset after age 65 is rare.

IBS is common among patients with alcohol abuse disorder (32%),² chronic fatigue syndrome (92%), fibromyalgia (77%), or temporomandibular joint syndrome (64%).³ Seventy percent of patients with IBS are women.⁴ Chronic pelvic pain, dyspareunia, dysmenorrhea, or a history of abdominal surgeries are risk factors for IBS in women.

LINK BETWEEN IBS AND MENTAL ILLNESS

Although mental illness often coexists with IBS, no cause-effect relationship has been shown.⁵

IBS is often preceded by stressful life events, such as family death or divorce,³ and some believe IBS is a precursor to numerous psychiatric disorders. Generalized anxiety disorder, major depression, panic disorder, social phobia, somatization disorder, or dysthymia have been diagnosed in most IBS patients.²

CASE 1: IBS AND DEPRESSION

Ms. R, age 55, has had IBS for 10 years. She has occasional diarrhea and abdominal cramps relieved by bowel movements. She is taking a bulking agent but still sometimes suffers abdominal pain.

She is referred to a psychiatrist after complaining of fatigue, loss of interest in hobbies, and crying spells for 2 months. She denies suicidal ideations. Her referring physician reports that she is taking conjugated estrogens to manage menopause symptoms. She denies any recent stressful life events. Thyroid function, glucose, and CBC are normal.

The challenge: Deciding which to treat first—the IBS symptoms or the depression—and how.

Discussion: The predominant symptom (in Ms. R’s case, abdominal pain) can help determine choice of medication. Bulk-forming agents, antispasmodics, barbiturates, benzodiazepines, and serotonin reuptake inhibitors have historically been used to treat IBS,⁶ but scant evidence supports their use.

Obtaining a thorough prescription history from the primary care physician, OB/GYN, and other treatment team members is critical before formulating a treatment plan. Ms. R’s estrogen use will not affect the choice of psychotropic or IBS medication because there are no significant interactions between estrogen and these classes of drugs.

Ms. R’s abdominal pain and depression can be treated simultaneously. Randomized, controlled trials have demonstrated that tricyclic antidepressants reduce abdominal pain and that behavioral therapy (relaxation therapy, hypnotherapy, and cognitive-behavioral therapy) may relieve individual IBS symptoms.⁷

Case 1 concluded: After reviewing Ms. R’s medications, the psychiatrist starts:

• desipramine, 50 mg at bedtime, to minimize anticholinergic side effects
• and short-term psychotherapy, which helped her identify support mechanisms and ways to better balance her life stresses.

After 6 weeks, her Beck Depression Inventory score improved from 30 at baseline to 8. She reports her abdominal pain is “the best it has been in 10 years.” Six months after diagnosis, she continues to take desipramine and is doing well.

CASE 2: IBS, DEPRESSION, AND PSYCHOSIS

Ms. H, age 32, is referred to a psychiatrist for treatment of depression with paranoid features.

Four years ago, a gastroenterologist diagnosed her as having IBS. She experiences frequent diarrhea and lower abdominal cramping. For 2 years she has been taking the antimuscarinic dicyclomine, 10 mg tid, which has provided some relief from her cramps. An estimated 20 diarrhea attacks per day leaves her housebound much of the time, however.

She reports fatigue, loss of interest in hobbies across 2 months, and paranoid thinking. She denies hallucinations or delusions but believes that her teenage children are discussing her “sickness” and plotting to “drive her crazy.” She is not suicidal.

The challenge: Treating Ms. H’s depression and paranoia while avoiding drug-drug interactions.

Discussion: Adverse drug-drug interactions can occur when prescribing psychotropics to patients with IBS (Table 1). Additive constipation, diarrhea, abdominal pain, and sedation are common interactions between psychotropics and the 5-HT3 antagonists and 5HT4 agonists commonly prescribed for IBS.

Table 1

Interactions between psychotropics and agents prescribed for IBS

Box

Other than fiber supplements, most traditional IBS medications are sedating and are associated with anticholinergic side effects. In Ms. H’s case, extreme caution is necessary before prescribing an antidepressant or antipsychotic because of dicyclomine’s additive sedating effects.

Case 2 concluded: After a thorough initial patient interview, the psychiatrist elects to treat Ms. H’s major depression with an antidepressant but delays the use of an antipsychotic to avoid additive sedation.

After talking with Ms. H’s family physician, the psychiatrist stops her dicyclomine and starts sertraline, 100 mg/d. She tolerates the sertraline well and the dosage is titrated across 1 month to 200 mg/d.

Four weeks later, Ms. H’s Beck Depression Inventory score has improved from 26 at baseline to 5, but her paranoid thoughts and frequent diarrhea persist. The psychiatrist adds low-dose olanzapine (5 mg at bedtime) to minimize extrapyramidal side effects. One month later, her depression and paranoia have resolved.

Ms. H’s gastroenterologist instructs her to begin taking alosetron, 1 mg bid, for her continued frequent diarrhea. Adding this agent to her sertraline/olanzapine regimen can lead to additive constipation and abdominal pain, so the psychiatrist monitors her psychiatric medications. One month later, she reports that her affect is much improved and her diarrhea is “gone.”

CASE 3: DEPRESSION AND ABDOMINAL PAIN

Mr. J, age 52, has had depression for 1 year. His depressive symptoms have improved significantly on fluoxetine, 20 mg/d; he once again enjoys life and has a more positive outlook.

The patient was in reasonably good health until about 1 month ago, when he began to experience abdominal pain. He has lost 14 lbs over the past month. He is not taking other medications.

The challenge: Find the cause of Mr. J’s persistent abdominal pain without undermining depression therapy.

Discussion: Although Mr. J’s symptoms might be side effects of fluoxetine, his abdominal pain and weight loss >10 lbs within 1 month are cause for concern. The American College of Gastroenterology has identified six alarm symptoms that could point to a serious medical problem in patients with severe abdominal pain (Box).⁷

Patients who exhibit any of these symptoms should be referred for endoscopic and stool studies. Colon cancer screening should be considered for all patients age 50 and older.

Patients with IBS usually present first to their primary care physicians with abdominal pain and altered bowel habits. These symptoms can occur in many gastrointestinal and systemic illnesses (Table 2).⁸

Table 2

Diagnosing irritable bowel syndrome: What to rule out

Case 3 concluded: The psychiatrist and primary care physician consult a gastroenterologist, who performs a colonoscopy and identifies a resectable Duke’s Class B adenocarcinoma in the transverse colon. A partial colectomy is performed.

Three years later, Mr. J is cancer-free and his depression is stable. The psychiatrist advises him to keep taking fluoxetine, 20 mg/d, because the stress of his cancer therapy increases the risk of depression recurrence.

Related resources

• National Institute of Diabetes and Digestive and Kidney Diseases —Irritable Bowel Syndrome www.niddk.nih.gov/health/digest/pubs/irrbowel/irrbowel.htm

Drug brand names

• Alosetron • Lotronex
• Aripiprazole • Abilify
• Buspirone • BuSpar
• Desipramine • Norpramin
• Dicyclomine • Bentyl
• Fluoxetine • Prozac
• Olanzapine • Zyprexa
• Sertraline • Zoloft

Disclosure

The author reports no financial relationship with any company whose products are mentioned in this article or with manufacturers of competing products.

Psychiatrists often treat patients with irritable bowel syndrome (IBS) and an accompanying mental illness. Knowledge of available treatments and communication with the referring doctor are crucial to treating both the IBS symptoms and the comorbidity.

This article presents three cases that illustrate the challenges of identifying target symptoms, avoiding drug-drug interactions, ruling out serious underlying medical problems, and formulating treatment.

WHO GETS IBS?

Approximately 12% of the United States population reports IBS symptoms (abdominal pain, bloating, altered bowel habits).¹ These symptoms begin before age 35 in most patients and during childhood in some. Onset after age 65 is rare.

IBS is common among patients with alcohol abuse disorder (32%),² chronic fatigue syndrome (92%), fibromyalgia (77%), or temporomandibular joint syndrome (64%).³ Seventy percent of patients with IBS are women.⁴ Chronic pelvic pain, dyspareunia, dysmenorrhea, or a history of abdominal surgeries are risk factors for IBS in women.

LINK BETWEEN IBS AND MENTAL ILLNESS

Although mental illness often coexists with IBS, no cause-effect relationship has been shown.⁵

IBS is often preceded by stressful life events, such as family death or divorce,³ and some believe IBS is a precursor to numerous psychiatric disorders. Generalized anxiety disorder, major depression, panic disorder, social phobia, somatization disorder, or dysthymia have been diagnosed in most IBS patients.²

CASE 1: IBS AND DEPRESSION

Ms. R, age 55, has had IBS for 10 years. She has occasional diarrhea and abdominal cramps relieved by bowel movements. She is taking a bulking agent but still sometimes suffers abdominal pain.

She is referred to a psychiatrist after complaining of fatigue, loss of interest in hobbies, and crying spells for 2 months. She denies suicidal ideations. Her referring physician reports that she is taking conjugated estrogens to manage menopause symptoms. She denies any recent stressful life events. Thyroid function, glucose, and CBC are normal.

The challenge: Deciding which to treat first—the IBS symptoms or the depression—and how.

Discussion: The predominant symptom (in Ms. R’s case, abdominal pain) can help determine choice of medication. Bulk-forming agents, antispasmodics, barbiturates, benzodiazepines, and serotonin reuptake inhibitors have historically been used to treat IBS,⁶ but scant evidence supports their use.

Obtaining a thorough prescription history from the primary care physician, OB/GYN, and other treatment team members is critical before formulating a treatment plan. Ms. R’s estrogen use will not affect the choice of psychotropic or IBS medication because there are no significant interactions between estrogen and these classes of drugs.

Ms. R’s abdominal pain and depression can be treated simultaneously. Randomized, controlled trials have demonstrated that tricyclic antidepressants reduce abdominal pain and that behavioral therapy (relaxation therapy, hypnotherapy, and cognitive-behavioral therapy) may relieve individual IBS symptoms.⁷

Case 1 concluded: After reviewing Ms. R’s medications, the psychiatrist starts:

• desipramine, 50 mg at bedtime, to minimize anticholinergic side effects
• and short-term psychotherapy, which helped her identify support mechanisms and ways to better balance her life stresses.

After 6 weeks, her Beck Depression Inventory score improved from 30 at baseline to 8. She reports her abdominal pain is “the best it has been in 10 years.” Six months after diagnosis, she continues to take desipramine and is doing well.

CASE 2: IBS, DEPRESSION, AND PSYCHOSIS

Ms. H, age 32, is referred to a psychiatrist for treatment of depression with paranoid features.

Four years ago, a gastroenterologist diagnosed her as having IBS. She experiences frequent diarrhea and lower abdominal cramping. For 2 years she has been taking the antimuscarinic dicyclomine, 10 mg tid, which has provided some relief from her cramps. An estimated 20 diarrhea attacks per day leaves her housebound much of the time, however.

She reports fatigue, loss of interest in hobbies across 2 months, and paranoid thinking. She denies hallucinations or delusions but believes that her teenage children are discussing her “sickness” and plotting to “drive her crazy.” She is not suicidal.

The challenge: Treating Ms. H’s depression and paranoia while avoiding drug-drug interactions.

Discussion: Adverse drug-drug interactions can occur when prescribing psychotropics to patients with IBS (Table 1). Additive constipation, diarrhea, abdominal pain, and sedation are common interactions between psychotropics and the 5-HT3 antagonists and 5HT4 agonists commonly prescribed for IBS.

Table 1

Interactions between psychotropics and agents prescribed for IBS

Box

Other than fiber supplements, most traditional IBS medications are sedating and are associated with anticholinergic side effects. In Ms. H’s case, extreme caution is necessary before prescribing an antidepressant or antipsychotic because of dicyclomine’s additive sedating effects.

Case 2 concluded: After a thorough initial patient interview, the psychiatrist elects to treat Ms. H’s major depression with an antidepressant but delays the use of an antipsychotic to avoid additive sedation.

After talking with Ms. H’s family physician, the psychiatrist stops her dicyclomine and starts sertraline, 100 mg/d. She tolerates the sertraline well and the dosage is titrated across 1 month to 200 mg/d.

Four weeks later, Ms. H’s Beck Depression Inventory score has improved from 26 at baseline to 5, but her paranoid thoughts and frequent diarrhea persist. The psychiatrist adds low-dose olanzapine (5 mg at bedtime) to minimize extrapyramidal side effects. One month later, her depression and paranoia have resolved.

Ms. H’s gastroenterologist instructs her to begin taking alosetron, 1 mg bid, for her continued frequent diarrhea. Adding this agent to her sertraline/olanzapine regimen can lead to additive constipation and abdominal pain, so the psychiatrist monitors her psychiatric medications. One month later, she reports that her affect is much improved and her diarrhea is “gone.”

CASE 3: DEPRESSION AND ABDOMINAL PAIN

Mr. J, age 52, has had depression for 1 year. His depressive symptoms have improved significantly on fluoxetine, 20 mg/d; he once again enjoys life and has a more positive outlook.

The patient was in reasonably good health until about 1 month ago, when he began to experience abdominal pain. He has lost 14 lbs over the past month. He is not taking other medications.

The challenge: Find the cause of Mr. J’s persistent abdominal pain without undermining depression therapy.

Discussion: Although Mr. J’s symptoms might be side effects of fluoxetine, his abdominal pain and weight loss >10 lbs within 1 month are cause for concern. The American College of Gastroenterology has identified six alarm symptoms that could point to a serious medical problem in patients with severe abdominal pain (Box).⁷

Patients who exhibit any of these symptoms should be referred for endoscopic and stool studies. Colon cancer screening should be considered for all patients age 50 and older.

Patients with IBS usually present first to their primary care physicians with abdominal pain and altered bowel habits. These symptoms can occur in many gastrointestinal and systemic illnesses (Table 2).⁸

Table 2

Diagnosing irritable bowel syndrome: What to rule out

Case 3 concluded: The psychiatrist and primary care physician consult a gastroenterologist, who performs a colonoscopy and identifies a resectable Duke’s Class B adenocarcinoma in the transverse colon. A partial colectomy is performed.

Three years later, Mr. J is cancer-free and his depression is stable. The psychiatrist advises him to keep taking fluoxetine, 20 mg/d, because the stress of his cancer therapy increases the risk of depression recurrence.

Related resources

• National Institute of Diabetes and Digestive and Kidney Diseases —Irritable Bowel Syndrome www.niddk.nih.gov/health/digest/pubs/irrbowel/irrbowel.htm

Drug brand names

• Alosetron • Lotronex
• Aripiprazole • Abilify
• Buspirone • BuSpar
• Desipramine • Norpramin
• Dicyclomine • Bentyl
• Fluoxetine • Prozac
• Olanzapine • Zyprexa
• Sertraline • Zoloft

Disclosure

The author reports no financial relationship with any company whose products are mentioned in this article or with manufacturers of competing products.

Psychiatrists often treat patients with irritable bowel syndrome (IBS) and an accompanying mental illness. Knowledge of available treatments and communication with the referring doctor are crucial to treating both the IBS symptoms and the comorbidity.

This article presents three cases that illustrate the challenges of identifying target symptoms, avoiding drug-drug interactions, ruling out serious underlying medical problems, and formulating treatment.

WHO GETS IBS?

Approximately 12% of the United States population reports IBS symptoms (abdominal pain, bloating, altered bowel habits).¹ These symptoms begin before age 35 in most patients and during childhood in some. Onset after age 65 is rare.

IBS is common among patients with alcohol abuse disorder (32%),² chronic fatigue syndrome (92%), fibromyalgia (77%), or temporomandibular joint syndrome (64%).³ Seventy percent of patients with IBS are women.⁴ Chronic pelvic pain, dyspareunia, dysmenorrhea, or a history of abdominal surgeries are risk factors for IBS in women.

LINK BETWEEN IBS AND MENTAL ILLNESS

Although mental illness often coexists with IBS, no cause-effect relationship has been shown.⁵

IBS is often preceded by stressful life events, such as family death or divorce,³ and some believe IBS is a precursor to numerous psychiatric disorders. Generalized anxiety disorder, major depression, panic disorder, social phobia, somatization disorder, or dysthymia have been diagnosed in most IBS patients.²

CASE 1: IBS AND DEPRESSION

Ms. R, age 55, has had IBS for 10 years. She has occasional diarrhea and abdominal cramps relieved by bowel movements. She is taking a bulking agent but still sometimes suffers abdominal pain.

She is referred to a psychiatrist after complaining of fatigue, loss of interest in hobbies, and crying spells for 2 months. She denies suicidal ideations. Her referring physician reports that she is taking conjugated estrogens to manage menopause symptoms. She denies any recent stressful life events. Thyroid function, glucose, and CBC are normal.

The challenge: Deciding which to treat first—the IBS symptoms or the depression—and how.

Discussion: The predominant symptom (in Ms. R’s case, abdominal pain) can help determine choice of medication. Bulk-forming agents, antispasmodics, barbiturates, benzodiazepines, and serotonin reuptake inhibitors have historically been used to treat IBS,⁶ but scant evidence supports their use.

Obtaining a thorough prescription history from the primary care physician, OB/GYN, and other treatment team members is critical before formulating a treatment plan. Ms. R’s estrogen use will not affect the choice of psychotropic or IBS medication because there are no significant interactions between estrogen and these classes of drugs.

Ms. R’s abdominal pain and depression can be treated simultaneously. Randomized, controlled trials have demonstrated that tricyclic antidepressants reduce abdominal pain and that behavioral therapy (relaxation therapy, hypnotherapy, and cognitive-behavioral therapy) may relieve individual IBS symptoms.⁷

Case 1 concluded: After reviewing Ms. R’s medications, the psychiatrist starts:

• desipramine, 50 mg at bedtime, to minimize anticholinergic side effects
• and short-term psychotherapy, which helped her identify support mechanisms and ways to better balance her life stresses.

After 6 weeks, her Beck Depression Inventory score improved from 30 at baseline to 8. She reports her abdominal pain is “the best it has been in 10 years.” Six months after diagnosis, she continues to take desipramine and is doing well.

CASE 2: IBS, DEPRESSION, AND PSYCHOSIS

Ms. H, age 32, is referred to a psychiatrist for treatment of depression with paranoid features.

Four years ago, a gastroenterologist diagnosed her as having IBS. She experiences frequent diarrhea and lower abdominal cramping. For 2 years she has been taking the antimuscarinic dicyclomine, 10 mg tid, which has provided some relief from her cramps. An estimated 20 diarrhea attacks per day leaves her housebound much of the time, however.

She reports fatigue, loss of interest in hobbies across 2 months, and paranoid thinking. She denies hallucinations or delusions but believes that her teenage children are discussing her “sickness” and plotting to “drive her crazy.” She is not suicidal.

The challenge: Treating Ms. H’s depression and paranoia while avoiding drug-drug interactions.

Discussion: Adverse drug-drug interactions can occur when prescribing psychotropics to patients with IBS (Table 1). Additive constipation, diarrhea, abdominal pain, and sedation are common interactions between psychotropics and the 5-HT3 antagonists and 5HT4 agonists commonly prescribed for IBS.

Table 1

Interactions between psychotropics and agents prescribed for IBS

Box

Other than fiber supplements, most traditional IBS medications are sedating and are associated with anticholinergic side effects. In Ms. H’s case, extreme caution is necessary before prescribing an antidepressant or antipsychotic because of dicyclomine’s additive sedating effects.

Case 2 concluded: After a thorough initial patient interview, the psychiatrist elects to treat Ms. H’s major depression with an antidepressant but delays the use of an antipsychotic to avoid additive sedation.

After talking with Ms. H’s family physician, the psychiatrist stops her dicyclomine and starts sertraline, 100 mg/d. She tolerates the sertraline well and the dosage is titrated across 1 month to 200 mg/d.

Four weeks later, Ms. H’s Beck Depression Inventory score has improved from 26 at baseline to 5, but her paranoid thoughts and frequent diarrhea persist. The psychiatrist adds low-dose olanzapine (5 mg at bedtime) to minimize extrapyramidal side effects. One month later, her depression and paranoia have resolved.

Ms. H’s gastroenterologist instructs her to begin taking alosetron, 1 mg bid, for her continued frequent diarrhea. Adding this agent to her sertraline/olanzapine regimen can lead to additive constipation and abdominal pain, so the psychiatrist monitors her psychiatric medications. One month later, she reports that her affect is much improved and her diarrhea is “gone.”

CASE 3: DEPRESSION AND ABDOMINAL PAIN

Mr. J, age 52, has had depression for 1 year. His depressive symptoms have improved significantly on fluoxetine, 20 mg/d; he once again enjoys life and has a more positive outlook.

The patient was in reasonably good health until about 1 month ago, when he began to experience abdominal pain. He has lost 14 lbs over the past month. He is not taking other medications.

The challenge: Find the cause of Mr. J’s persistent abdominal pain without undermining depression therapy.

Discussion: Although Mr. J’s symptoms might be side effects of fluoxetine, his abdominal pain and weight loss >10 lbs within 1 month are cause for concern. The American College of Gastroenterology has identified six alarm symptoms that could point to a serious medical problem in patients with severe abdominal pain (Box).⁷

Patients who exhibit any of these symptoms should be referred for endoscopic and stool studies. Colon cancer screening should be considered for all patients age 50 and older.

Patients with IBS usually present first to their primary care physicians with abdominal pain and altered bowel habits. These symptoms can occur in many gastrointestinal and systemic illnesses (Table 2).⁸

Table 2

Diagnosing irritable bowel syndrome: What to rule out

Case 3 concluded: The psychiatrist and primary care physician consult a gastroenterologist, who performs a colonoscopy and identifies a resectable Duke’s Class B adenocarcinoma in the transverse colon. A partial colectomy is performed.

Three years later, Mr. J is cancer-free and his depression is stable. The psychiatrist advises him to keep taking fluoxetine, 20 mg/d, because the stress of his cancer therapy increases the risk of depression recurrence.

Related resources

• National Institute of Diabetes and Digestive and Kidney Diseases —Irritable Bowel Syndrome www.niddk.nih.gov/health/digest/pubs/irrbowel/irrbowel.htm

Drug brand names

• Alosetron • Lotronex
• Aripiprazole • Abilify
• Buspirone • BuSpar
• Desipramine • Norpramin
• Dicyclomine • Bentyl
• Fluoxetine • Prozac
• Olanzapine • Zyprexa
• Sertraline • Zoloft

Disclosure

The author reports no financial relationship with any company whose products are mentioned in this article or with manufacturers of competing products.

Otitis externa (OE), also referred to as external otitis, is inflammation of the auricle, external ear, or tympanic membrane. The severity can range from mild inflammation to life-threatening infection.¹ It is commonly seen by family physicians and affects 4 out of each 1000 Americans every year.² In most cases the significant pain of OE compels the patient to seek care urgently.

OE can be categorized as localized or diffuse. When it persists for more than 6 months, it is considered chronic and is more commonly bilateral. It is thought to be caused by local trauma to the external canal, diabetes, high humidity, loss of the canal’s protective coating of cerumen, eczema, use of a hearing aid or stethoscope, or glandular obstruction. It is commonly seen in swimmers, particularly in the summer months.¹ The most frequent symptoms are discharge, pain, hearing loss, itching, and tinnitus.

Necrotizing (malignant) otitis externa (NOE) is the most severe form of OE and is most often seen in elderly patients with diabetes. One case series in a referral population found a mortality rate of 53%.3 Pain, purulent discharge, bilateral involvement, and external canal granulation tissue are common symptoms.

Pathophysiology

The ear canal is a blind sac with an anterior recess. Trauma to the canal, accumulation of keratin, or a change in pH can trigger inflammation and infection. One study⁴ found that aerobic bacteria account for 91% of bacterial causes; anaerobes, 4%; and mixed infections, 4%. The most common offending organisms are Pseudomonas aeruginosa (50%), Staphylococcus aureus (23%), anaerobes and gram-negative organisms (12.5%), and yeast, such as Aspergillus and Candida (12.5%). The increased pH of pool water is believed to make infection more likely, since bacteriologic studies fail to show a direct link between swimming pool contamination and the organisms of OE.

Diagnosis

There are no published studies of the accuracy of the medical history, physical examination, or office laboratory tests for the diagnosis of OE. Diagnosis is usually made based on physical examination findings: pain on movement of the auricle, edema, redness, and foul-smelling discharge.⁵ Swelling often obscures the tympanic membrane.

NOE is also a clinical diagnosis and requires a high index of suspicion. A study by Zaky and colleagues³ considered 2 new cases and 32 that were retrospectively reviewed from the literature. They found the following frequencies of symptoms: pain (100%), purulent discharge (97%), bilateral involvement (21%), and a polyp in the external canal (88%). Diabetes was common in this group of patients (82%), confirming that it is consistently a predisposing risk factor, and 91% of these patients were aged 55 years and older.

Few papers have been published concerning diagnostic studies for NOE. One found that temporal radiographs and tomograms are positive in most cases of NOE but were not necessary for diagnosis.⁶ The erythrocyte sedimentation rate is usually increased,³ but this is true in many other illnesses. Many studies^3,8-9,31-35 have reported that Pseudomonas is the primary offending organism for NOE. Because most ear cultures are positive for Pseudomonas, these cultures are of questionable value.¹⁰

There are 4 studies that consider more aggressive diagnostic testing for NOE using conventional temporal radiographs, tomographic temporal radiographs, qualitative and single photon emission computed tomography⁶⁷ gallium scans, and qualitative and quantitative⁹⁹ technetium bone scans.^6-9 These studies were limited by the use of unclear⁷ or poor quality^6,8 reference standards (radiograph or poor response to antibiotics). The diagnosis of NOE does not require additional studies. Expert opinion supports a diagnosis based on the history and physical examination and poor response to treatment. The most common symptom of NOE is persistent pain that is constant and severe. The leukocyte count may be normal or mildly elevated.³ Physicians should consider the diagnosis of NOE in any patient with diabetes who has OE, particularly older patients. Characteristics of OE and NOE are presented in Table 1.

Treatment

Otitis Externa

The main principles of treatment are local cleansing of debris, drainage of the infection, re-establishment of the normal acidic environment, use of topical and systemic antimicrobials, and prevention of recurrent infections. The evidence regarding these treatments is summarized in Table 2. The best evidence (grade of evidence: A) demonstrates equivalent results with ear cleaning, an ear wick, and any of the choices of topical agents^12-13—acidifying agents, antibiotics, antibiotic and steroid combinations, or antifungal agents. Frequent dosing (3 to 4 times daily) for at least 4 days is supported by the studies. Two studies demonstrated equivalent efficacy with topical ciprofloxacin or ofloxacin dosed twice daily compared with antibiotic and steroid combinations dosed 4 times daily.^16-17 However, these agents are also more expensive than older topical antibiotics. The evidence for single topical treatments and oral antibiotics is weaker^14-29 (grade of evidence: B).

Physicians should treat patients with one of the following regimens for at least 4 days:

• ear cleaning + ear wick + acidifying agent dosed 4 times daily
• ear cleaning + ear wick + topical antibiotic dosed 4 times daily (twice daily if quinolone)
• ear cleaning + ear wick + topical antibiotic/steroid combination dosed 4 times daily (twice daily if quinolone)

The ear is best cleaned by simply irrigating the canal. Be sure to look for a foreign body, particularly in younger patients. For a wick, use either the Pope ear wick (Merocel Corporation, Mystic, Conn) or a fourth-inch sterile gauze. The wick helps draw topical medications into the affected canal, particularly when it is obstructed. The patient should return in approximately 2 days for removal of the wick and reassessment. Do not forget analgesics; this is a painful condition.

Necrotizing Otitis Externa

The treatment for NOE must be aggressive. As the infection invades through the soft tissues into surrounding bony structures, it can be life threatening.¹⁰ The evidence for various treatments is presented in Table 3. The studies are weaker than those for treatment of otitis externa (grade of recommendations: B and C). They support twice daily dosing with oral ofloxacin 400 mg orally twice daily or ciprofloxacin 750 mg orally twice daily for up to 3 months.^31-33 There is weak evidence that hyperbaric oxygen is effective.³⁴ Intravenous anti-Pseudomonal antibiotics are often used initially, based on expert opinion (grade: D) and the high mortality rate.

The oral fluoroquinolones (ofloxacin and ciprofloxacin) show promise for treating NOE. The choice of parenteral or oral antibiotics still rests with clinician judgment, based on the patient’s clinical presentation. If oral antibiotics are started, the length of treatment should be based on the severity of illness.

Prognosis

The prognosis for cure of OE is excellent, although the actual natural history of untreated disease has not been studied. OE complicated by NEO is more common in persons with diabetes who have a persistent course and granulation tissue visualized in the external auditory canal. Untreated NEO can lead to osteomyelitis and paralysis of cranial nerves. Death can result from sepsis and central nervous system infection.

Otitis externa (OE), also referred to as external otitis, is inflammation of the auricle, external ear, or tympanic membrane. The severity can range from mild inflammation to life-threatening infection.¹ It is commonly seen by family physicians and affects 4 out of each 1000 Americans every year.² In most cases the significant pain of OE compels the patient to seek care urgently.

OE can be categorized as localized or diffuse. When it persists for more than 6 months, it is considered chronic and is more commonly bilateral. It is thought to be caused by local trauma to the external canal, diabetes, high humidity, loss of the canal’s protective coating of cerumen, eczema, use of a hearing aid or stethoscope, or glandular obstruction. It is commonly seen in swimmers, particularly in the summer months.¹ The most frequent symptoms are discharge, pain, hearing loss, itching, and tinnitus.

Necrotizing (malignant) otitis externa (NOE) is the most severe form of OE and is most often seen in elderly patients with diabetes. One case series in a referral population found a mortality rate of 53%.3 Pain, purulent discharge, bilateral involvement, and external canal granulation tissue are common symptoms.

Pathophysiology

The ear canal is a blind sac with an anterior recess. Trauma to the canal, accumulation of keratin, or a change in pH can trigger inflammation and infection. One study⁴ found that aerobic bacteria account for 91% of bacterial causes; anaerobes, 4%; and mixed infections, 4%. The most common offending organisms are Pseudomonas aeruginosa (50%), Staphylococcus aureus (23%), anaerobes and gram-negative organisms (12.5%), and yeast, such as Aspergillus and Candida (12.5%). The increased pH of pool water is believed to make infection more likely, since bacteriologic studies fail to show a direct link between swimming pool contamination and the organisms of OE.

Diagnosis

There are no published studies of the accuracy of the medical history, physical examination, or office laboratory tests for the diagnosis of OE. Diagnosis is usually made based on physical examination findings: pain on movement of the auricle, edema, redness, and foul-smelling discharge.⁵ Swelling often obscures the tympanic membrane.

NOE is also a clinical diagnosis and requires a high index of suspicion. A study by Zaky and colleagues³ considered 2 new cases and 32 that were retrospectively reviewed from the literature. They found the following frequencies of symptoms: pain (100%), purulent discharge (97%), bilateral involvement (21%), and a polyp in the external canal (88%). Diabetes was common in this group of patients (82%), confirming that it is consistently a predisposing risk factor, and 91% of these patients were aged 55 years and older.

Few papers have been published concerning diagnostic studies for NOE. One found that temporal radiographs and tomograms are positive in most cases of NOE but were not necessary for diagnosis.⁶ The erythrocyte sedimentation rate is usually increased,³ but this is true in many other illnesses. Many studies^3,8-9,31-35 have reported that Pseudomonas is the primary offending organism for NOE. Because most ear cultures are positive for Pseudomonas, these cultures are of questionable value.¹⁰

There are 4 studies that consider more aggressive diagnostic testing for NOE using conventional temporal radiographs, tomographic temporal radiographs, qualitative and single photon emission computed tomography⁶⁷ gallium scans, and qualitative and quantitative⁹⁹ technetium bone scans.^6-9 These studies were limited by the use of unclear⁷ or poor quality^6,8 reference standards (radiograph or poor response to antibiotics). The diagnosis of NOE does not require additional studies. Expert opinion supports a diagnosis based on the history and physical examination and poor response to treatment. The most common symptom of NOE is persistent pain that is constant and severe. The leukocyte count may be normal or mildly elevated.³ Physicians should consider the diagnosis of NOE in any patient with diabetes who has OE, particularly older patients. Characteristics of OE and NOE are presented in Table 1.

Treatment

Otitis Externa

The main principles of treatment are local cleansing of debris, drainage of the infection, re-establishment of the normal acidic environment, use of topical and systemic antimicrobials, and prevention of recurrent infections. The evidence regarding these treatments is summarized in Table 2. The best evidence (grade of evidence: A) demonstrates equivalent results with ear cleaning, an ear wick, and any of the choices of topical agents^12-13—acidifying agents, antibiotics, antibiotic and steroid combinations, or antifungal agents. Frequent dosing (3 to 4 times daily) for at least 4 days is supported by the studies. Two studies demonstrated equivalent efficacy with topical ciprofloxacin or ofloxacin dosed twice daily compared with antibiotic and steroid combinations dosed 4 times daily.^16-17 However, these agents are also more expensive than older topical antibiotics. The evidence for single topical treatments and oral antibiotics is weaker^14-29 (grade of evidence: B).

Physicians should treat patients with one of the following regimens for at least 4 days:

• ear cleaning + ear wick + acidifying agent dosed 4 times daily
• ear cleaning + ear wick + topical antibiotic dosed 4 times daily (twice daily if quinolone)
• ear cleaning + ear wick + topical antibiotic/steroid combination dosed 4 times daily (twice daily if quinolone)

The ear is best cleaned by simply irrigating the canal. Be sure to look for a foreign body, particularly in younger patients. For a wick, use either the Pope ear wick (Merocel Corporation, Mystic, Conn) or a fourth-inch sterile gauze. The wick helps draw topical medications into the affected canal, particularly when it is obstructed. The patient should return in approximately 2 days for removal of the wick and reassessment. Do not forget analgesics; this is a painful condition.

Necrotizing Otitis Externa

The treatment for NOE must be aggressive. As the infection invades through the soft tissues into surrounding bony structures, it can be life threatening.¹⁰ The evidence for various treatments is presented in Table 3. The studies are weaker than those for treatment of otitis externa (grade of recommendations: B and C). They support twice daily dosing with oral ofloxacin 400 mg orally twice daily or ciprofloxacin 750 mg orally twice daily for up to 3 months.^31-33 There is weak evidence that hyperbaric oxygen is effective.³⁴ Intravenous anti-Pseudomonal antibiotics are often used initially, based on expert opinion (grade: D) and the high mortality rate.

The oral fluoroquinolones (ofloxacin and ciprofloxacin) show promise for treating NOE. The choice of parenteral or oral antibiotics still rests with clinician judgment, based on the patient’s clinical presentation. If oral antibiotics are started, the length of treatment should be based on the severity of illness.

Prognosis

The prognosis for cure of OE is excellent, although the actual natural history of untreated disease has not been studied. OE complicated by NEO is more common in persons with diabetes who have a persistent course and granulation tissue visualized in the external auditory canal. Untreated NEO can lead to osteomyelitis and paralysis of cranial nerves. Death can result from sepsis and central nervous system infection.

Otitis externa (OE), also referred to as external otitis, is inflammation of the auricle, external ear, or tympanic membrane. The severity can range from mild inflammation to life-threatening infection.¹ It is commonly seen by family physicians and affects 4 out of each 1000 Americans every year.² In most cases the significant pain of OE compels the patient to seek care urgently.

OE can be categorized as localized or diffuse. When it persists for more than 6 months, it is considered chronic and is more commonly bilateral. It is thought to be caused by local trauma to the external canal, diabetes, high humidity, loss of the canal’s protective coating of cerumen, eczema, use of a hearing aid or stethoscope, or glandular obstruction. It is commonly seen in swimmers, particularly in the summer months.¹ The most frequent symptoms are discharge, pain, hearing loss, itching, and tinnitus.

Necrotizing (malignant) otitis externa (NOE) is the most severe form of OE and is most often seen in elderly patients with diabetes. One case series in a referral population found a mortality rate of 53%.3 Pain, purulent discharge, bilateral involvement, and external canal granulation tissue are common symptoms.

Pathophysiology

The ear canal is a blind sac with an anterior recess. Trauma to the canal, accumulation of keratin, or a change in pH can trigger inflammation and infection. One study⁴ found that aerobic bacteria account for 91% of bacterial causes; anaerobes, 4%; and mixed infections, 4%. The most common offending organisms are Pseudomonas aeruginosa (50%), Staphylococcus aureus (23%), anaerobes and gram-negative organisms (12.5%), and yeast, such as Aspergillus and Candida (12.5%). The increased pH of pool water is believed to make infection more likely, since bacteriologic studies fail to show a direct link between swimming pool contamination and the organisms of OE.

Diagnosis

There are no published studies of the accuracy of the medical history, physical examination, or office laboratory tests for the diagnosis of OE. Diagnosis is usually made based on physical examination findings: pain on movement of the auricle, edema, redness, and foul-smelling discharge.⁵ Swelling often obscures the tympanic membrane.

NOE is also a clinical diagnosis and requires a high index of suspicion. A study by Zaky and colleagues³ considered 2 new cases and 32 that were retrospectively reviewed from the literature. They found the following frequencies of symptoms: pain (100%), purulent discharge (97%), bilateral involvement (21%), and a polyp in the external canal (88%). Diabetes was common in this group of patients (82%), confirming that it is consistently a predisposing risk factor, and 91% of these patients were aged 55 years and older.

Few papers have been published concerning diagnostic studies for NOE. One found that temporal radiographs and tomograms are positive in most cases of NOE but were not necessary for diagnosis.⁶ The erythrocyte sedimentation rate is usually increased,³ but this is true in many other illnesses. Many studies^3,8-9,31-35 have reported that Pseudomonas is the primary offending organism for NOE. Because most ear cultures are positive for Pseudomonas, these cultures are of questionable value.¹⁰

There are 4 studies that consider more aggressive diagnostic testing for NOE using conventional temporal radiographs, tomographic temporal radiographs, qualitative and single photon emission computed tomography⁶⁷ gallium scans, and qualitative and quantitative⁹⁹ technetium bone scans.^6-9 These studies were limited by the use of unclear⁷ or poor quality^6,8 reference standards (radiograph or poor response to antibiotics). The diagnosis of NOE does not require additional studies. Expert opinion supports a diagnosis based on the history and physical examination and poor response to treatment. The most common symptom of NOE is persistent pain that is constant and severe. The leukocyte count may be normal or mildly elevated.³ Physicians should consider the diagnosis of NOE in any patient with diabetes who has OE, particularly older patients. Characteristics of OE and NOE are presented in Table 1.

Treatment

Otitis Externa

The main principles of treatment are local cleansing of debris, drainage of the infection, re-establishment of the normal acidic environment, use of topical and systemic antimicrobials, and prevention of recurrent infections. The evidence regarding these treatments is summarized in Table 2. The best evidence (grade of evidence: A) demonstrates equivalent results with ear cleaning, an ear wick, and any of the choices of topical agents^12-13—acidifying agents, antibiotics, antibiotic and steroid combinations, or antifungal agents. Frequent dosing (3 to 4 times daily) for at least 4 days is supported by the studies. Two studies demonstrated equivalent efficacy with topical ciprofloxacin or ofloxacin dosed twice daily compared with antibiotic and steroid combinations dosed 4 times daily.^16-17 However, these agents are also more expensive than older topical antibiotics. The evidence for single topical treatments and oral antibiotics is weaker^14-29 (grade of evidence: B).

Physicians should treat patients with one of the following regimens for at least 4 days:

• ear cleaning + ear wick + acidifying agent dosed 4 times daily
• ear cleaning + ear wick + topical antibiotic dosed 4 times daily (twice daily if quinolone)
• ear cleaning + ear wick + topical antibiotic/steroid combination dosed 4 times daily (twice daily if quinolone)

The ear is best cleaned by simply irrigating the canal. Be sure to look for a foreign body, particularly in younger patients. For a wick, use either the Pope ear wick (Merocel Corporation, Mystic, Conn) or a fourth-inch sterile gauze. The wick helps draw topical medications into the affected canal, particularly when it is obstructed. The patient should return in approximately 2 days for removal of the wick and reassessment. Do not forget analgesics; this is a painful condition.

Necrotizing Otitis Externa

The treatment for NOE must be aggressive. As the infection invades through the soft tissues into surrounding bony structures, it can be life threatening.¹⁰ The evidence for various treatments is presented in Table 3. The studies are weaker than those for treatment of otitis externa (grade of recommendations: B and C). They support twice daily dosing with oral ofloxacin 400 mg orally twice daily or ciprofloxacin 750 mg orally twice daily for up to 3 months.^31-33 There is weak evidence that hyperbaric oxygen is effective.³⁴ Intravenous anti-Pseudomonal antibiotics are often used initially, based on expert opinion (grade: D) and the high mortality rate.

The oral fluoroquinolones (ofloxacin and ciprofloxacin) show promise for treating NOE. The choice of parenteral or oral antibiotics still rests with clinician judgment, based on the patient’s clinical presentation. If oral antibiotics are started, the length of treatment should be based on the severity of illness.

Prognosis

The prognosis for cure of OE is excellent, although the actual natural history of untreated disease has not been studied. OE complicated by NEO is more common in persons with diabetes who have a persistent course and granulation tissue visualized in the external auditory canal. Untreated NEO can lead to osteomyelitis and paralysis of cranial nerves. Death can result from sepsis and central nervous system infection.