Irritable bowel syndrome (IBS) affects 8 to 14 percent of the population on any given day, and is the most common of all gastrointestinal ailments. Although IBS has been the focus of many investigational studies, little definitive information is available concerning etiology, diagnosis and treatment. In making this diagnosis of exclusion, an extensive list of gastrointestinal illnesses must be ruled out. Therefore, the diagnosis depends on a thorough history and physical examination. The nature of IBS requires a holistic treatment program, including nutrition, exercise, medication, behavior modification and emotional support. Since IBS is a recurring disease, the client should be helped to set realistic goals for treatment. The caring and supportive relationship between the health care practitioner and the client with IBS is essential to the success of treatment.