Irritable bowel syndrome.

Irritable bowel syndrome (IBS) is a common medical disorder that is associated with significant disability and health care costs. A practical approach to diagnosis and management of patients afflicted by this disorder has previously been hampered due to incomplete understanding of its pathophysiology, lack of diagnostic precision, and absence of specific treatments. Over the last decade, epidemiological, physiological, and psychosocial data have emerged to improve our understanding of this disorder and its treatment. IBS is currently believed to result from dysregulation of intestinal motor, sensory, and central nervous system function. Symptoms are due to both disturbances in intestinal motility and enhanced visceral sensitivity. Psychosocial factors, although not part of IBS per se, have an important role in modulating the illness experience and its clinical outcome. Use of multinational symptom-based "Rome" criteria has increased diagnostic specificity and has helped to minimize studies done to exclude other disease. Finally, treatment involves an integrated pharmacological and behavioral approach that is determined by the severity of the illness and its physiological and psychosocial determinants.