Irritable bowel syndrome: evaluation and treatment.

Irritable bowel syndrome is a common gastrointestinal disorder characterized by abdominal pain, bloating, and disturbed defecation in the absence of other medical conditions with similar presentations. Because physical findings and currently available diagnostic tests lack sufficient specificity for clinical use, the diagnosis of IBS is based on characteristic symptoms as outlined in several symptom-based criteria for IBS. When used in combination with a detailed history, physical examination, and limited diagnostic testing, these criteria are a valid method of diagnosing IBS. Once a confident diagnosis of IBS has been made, treatment of IBS should be based on the predominant symptom while taking into account the severity of symptoms and the degree of functional impairment both physically and psychologically. Most patients with IBS have mild symptoms and education, reassurance, dietary and lifestyle changes, and a therapeutic physician-patient relationship form the backbone of treatment. A smaller number of patients have moderate symptoms, which are typically intermittent, but may at times interrupt their normal activities. In addition to dietary and lifestyle modifications, pharmacologic intervention based on the predominant symptom (diarrhea, constipation, or pain) may be used to relieve symptoms. Finally, a small subset of patients has severe or intractable symptoms. These patients, often seen in tertiary referral centers, often have constant pain symptoms and psychosocial impairments. A multidisciplinary approach including pharmacologic treatments, psychologic treatments, and possibly a mental health or pain center involvement may be beneficial.