Irritable bowel syndrome is a biopsychosocial disorder characterized by dysregulation of intestinal motor, sensory, and central nervous system functions. It is associated with significant disability and health-care costs. The traditional diagnostic approach leads to excessive investigation for many patients. A reductionist approach of focusing on evaluation and treatment of a single mechanism is unlikely to prove effective. Identification of the characteristic symptom pattern is the key to cost-effective management. A strong patient-physician relationship is essential for a successful outcome. Optimal outcome is predicated on an individualized treatment plan that integrates pharmacologic and behavioral modalities.