Diagnosis and treatment of irritable bowel syndrome - includes patient information sheets

Author: Christine B. Dalton, Douglas A. Drossman
Date: Feb 15, 1997

Irritable bowel syndrome is a common disorder characterized by symptoms of abdominal pain with diarrhea and/or constipation. It is associated with significant disability and health care costs. A practical approach to diagnosis utilizes the symptom-based Rome criteria. Management of patients has been helped by recent findings relating to the pathophysiology of the disorder. Dysregulation of intestinal motor functions, sensory functions and central nervous system functions is currently believed to be the basis for irritable bowel symptoms. Symptoms are a result of both abnormal intestinal motility and enhanced visceral sensitivity. Psychosocial factors can affect the illness experience and the clinical outcome. An effective physician-patient relationship is required for a successful outcome. Individualized treatment involves an integrated pharmacologic and behavioral approach determined by the predominant symptom type, the severity of the symptoms and the degree of disability.

Irritable bowel syndrome is a common disorder characterized by symptoms of abdominal pain and disturbed defecation. It is part of a larger diagnostic group, the functional gastrointestinal disorders, which includes functional (noncardiac) chest pain, functional (nonulcer) dyspepsia, functional abdominal pain and functional anorectal pain. Functional gastrointestinal disorders are characterized by persistent or recurrent symptoms that are not explained by identifiable structural or biochemical abnormalities.

These disorders are associated with significant disability and health care costs. Over the past decade, epidemiologic, physiologic and psychosocial data have contributed to improved understanding and treatment of irritable bowel syndrome and other functional gastrointestinal disorders.

Definition

A new classification system, the Rome criteria,[1] has been developed by an international group of investigators to describe symptom patterns, clinical features and diagnostic criteria of 24 functional gastrointestinal disorders. The diagnostic Rome criteria for irritable bowel syndrome are shown in Table 1.

TABLE 1Rome Diagnostic Criteriafor Irritable Bowel SyndromeAt least three months ofcontinuous or recurrentsymptoms: Abdominal pain ordiscomfort that is: Relieved with defecation and/or Associated with a change in frequency of stool and/or Associated with a change in consistency of stool plusTwo or more of the following, on at leastone-fourth of occasions or days: Altered stool frequency (for research purposes, "altered" may be defined as more than three bowel movements each day or fewer than three bowel movements each week) Altered stool form (lumpy and hard, or loose and watery) Altered stool passage (straining, urgency or a feeling of incomplete evacuation) Passage of mucus Bloating or feeling of abdominal distention

Adapted from Drossman DA, Richter JE, et al., eds. Functional gastrointestinal disorders: diagnosis, pathophysiology and treatment: a multinational consensus. Boston: Little, Brown, 1994.

Epidemiology

Studies of the general population have led to estimates that as many as 10 to 20 percent of adults experience irritable bowel symptoms. Of these, less than one-half seek medical attention.[2] Factors that influence the consultation of a physician include the presence and degree of pain and psychologic conditions. Studies indicate that patients with irritable bowel syndrome constitute a large portion of a family physician's practice and account for more than one-fourth of all gastrointestinal referrals.

In Western societies, irritable bowel syndrome occurs almost twice as often in women as in men. Although its frequency diminishes with age, it is still common in the elderly. Over time, up to 30 percent of persons with irritable bowel symptoms become asymptomatic.[3]

The health care impact of irritable bowel syndrome is considerable. Persons with irritable bowel syndrome are significantly more likely to miss days from work or school and to visit their physicians for gastrointestinal and nongastrointestinal symptoms than persons without bowel symptoms.[4]

Pathophysiology

Irritable bowel syndrome is currently believed to result from dysregulation of intestinal motor and sensory functions as modulated by the central nervous system. Symptoms are a result of both disturbances in intestinal motility and enhanced visceral sensitivity.

ABNORMAL MOTILITY

Patients with irritable bowel syndrome have been shown to have increased motility and abnormal contractions in response to stimuli, including psychologic stress and physiologic factors. Patients with diarrhea-predominant irritable bowel syndrome have accelerated whole-gut transit times, while patients with constipation-predominant irritable bowel syndrome have delays in colonic transit.[5]

ENHANCED VISCERAL PERCEPTION

Some of the common clinical features of irritable bowel syndrome, such as severity of pain disproportionate to measured motility, suggest an increased sensitivity of the bowel.[6] In balloon distention studies, patients with irritable bowel syndrome report pain at significantly lower volumes than control subjects. Interestingly, symptoms often begin or worsen after intestinal infection or surgery, suggesting that inflammation or injury may be an activating factor in the development of visceral hypersensitivity.

ROLE OF PSYCHOSOCIAL FACTORS

Although psychologic stress can affect gastrointestinal function and produce symptoms in everyone, it does so to a greater degree in patients with irritable bowel syndrome. In addition, patients with irritable bowel syndrome have greater psychologic distress than healthy persons or persons with irritable bowel syndrome who do not seek health care.[7]

Assessing certain psychosocial factors at the initial visit can help the physician determine the effect, if any, these factors may have on the patient's condition. A useful format for addressing psychologic factors is shown in Table 2.[8] Psychosocial factors are neither diagnostic of irritable bowel syndrome nor the cause, but they can influence the way the illness is experienced, who will seek medical help and the eventual clinical outcome.

TABLE 2Questions That May Clarify the Psychosocial Situationof a Patient with Irritable Bowel SyndromeWhat is the patient's understanding of the illness? ( i.e., whatdoes the patient think is causing the symptoms?)Does the patient accept the idea that stress may play a role?Is there abnormal illness behavior? (i.e., pain is always a "10," patient demands that something be done right now, patient has a history of multiple visits to many doctors)How does the disorder affect daily function?What is the reason for the visit? (i.e., why is the patient here now?)Is there a concurrent psychologic diagnosis? (i.e., anxiety, depression)Is there a history of physical or sexual abuse? (such a history can contribute to persistent pain and refractoriness to treatment)

An ongoing relationship with a primary care physician who provides psychosocial support with brief but repeated visits is essential for the successful care of severely affected patients (Table 5).

Final Comment

The care of patients with irritable bowel syndrome can be particularly challenging to physicians. With a limited screening evaluation, a clear diagnosis based on symptom criteria, the development of an effective physician-patient relationship and symptomatic treatment with follow-up, these patients can be treated successfully. Optimal patient outcome depends on careful coordination of the physician's medical expertise and psychologic skills, as well as simple human understanding.

REFERENCES

[1.] Drossman DA, Richter JE, et al., eds. Functional gastrointestinal disorders: diagnosis, pathophysiology and treatment: a multinational consensus. Boston: Little, Brown, 1994.

[2.] Drossman DA, Thompson WG. The irritable bowel syndrome: review and a graduated multicomponent treatment approach. Ann Intern Med 1992; 116:1009-16.

[3.] Talley NJ. Functional gastrointestinal disorders. In: Grendell JH, McQuaid KR, Friedman SL, eds. Current diagnosis and treatment in gastroenterology. Stamford, Conn: Appleton & Lange, 1996:86-94.

[4.] Drossman DA, Li Z, Andruzzi E, Temple RD, Talley NJ, Thompson WG, et al. U.S. householder survey of functional gastrointestinal disorders. Prevalence, sociodemography, and health impact. Dig Dis Sci 1993;38:1569-80.

[5.] Whitehead WE, Schuster MM. Irritable bowel syndrome. In: Winawer SJ, ed. Management of gastrointestinal diseases. New York: Gower Medical, 1992:32.1-32.25.

[6.] Mayer EA, Gebhart GF. Basic and clinical aspects of visceral hyperalgesia. Gastroenterology 1994;107: 271-93.

[7.] Drossman DA. Irritable bowel syndrome. Gastroenterologist 1994; 2:315-26.

[8.] Drossman DA, Talley NJ, Olden KW, Leserman J, Barreiro MA. Sexual and physical abuse and gastrointestinal illness. Review and recommendations. Ann Intern Med 1995;123:782-94.

[9.] Camilleri M, Prather CM. The irritable bowel syndrome: mechanisms and a practical approach to management. Ann Intern Med 1992;116:1001-8.

[10.] Drossman DA, Camilleri M, Whitehead WE. American Gastroenterological Association technical review on irritable bowel syndrome. Gastroenterology (In Press).

[11.] Drossman DA. Diagnosing and treating patients with refractory functional gastrointestinal disorders. Ann Intern Med 1995;123:688-97.

Adapted from Drossman DA, Richter JE, et al., eds. Functional gastrointestinal disorders: diagnosis, pathophysiology and treatment: a multinational consensus. Boston: Little, Brown, 1994.

The Authors

CHRISTINE B. DALTON, P.A.-C. is a research instructor in the Department of Medicine at the University of North Carolina at Chapel Hill School of Medicine. She received physician assistant training at Bowman Gray School of Medicine of Wake Forest University, Winston-Salem, N.C.

DOUGLAS A. DROSSMAN, M.D. is a professor of medicine and psychiatry at the University of North Carolina at Chapel Hill School of Medicine. He earned his medical degree at Albert Einstein College of Medicine of Yeshiva University, Bronx, N.Y, and completed a fellowship in medicine and psychiatry (psychosomatic medicine) at the University of Rochester, Rochester School of Medicine and Dentistry, Rochester, N.Y, and a fellowship in gastroenterology at the University of North Carolina at Chapel Hill.

Address correspondence to Christine B. Dalton, PA.-C., Division of Digestive Diseases, 420 Burnett-Womack Bldg., Campus Box 7080, University of North Carolina at Chapel Hill. Chapel Hill NC 27599-7080.

COPYRIGHT 1997 American Academy of Family PhysiciansCOPYRIGHT 2004 Gale Group

 
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