Irritable bowel syndrome (IBS) is one of the most common diagnoses made in the primary care setting and is responsible for up to 40% of referrals to gastroenterologists. Approximately 70% of persons who meet the diagnostic criteria for IBS do not seek health care, and the remaining account for 12% of visits to primary care providers. IBS is a functional bowel disorder comprising abdominal pain associated with defecation or a change in bowel habit with features of disordered defecation and distension in the absence of any demonstrable abnormality. The diagnosis is based on clinical findings and the exclusion of other disorders. New pharmaceutical agents are available to treat the underlying disorder; however, the treatment of IBS still involves a comprehensive, multicomponent approach that includes medical management of dominant symptoms, dietary modifications, and, possibly, psychotherapy.