Strong evidence exists that the irritable bowel syndrome has an important psychological component. Firstly, about half of patients with the irritable bowel syndrome in a hospital clinic have psychiatric disorder when assessed by research criteria.1 This is two or three times greater than the prevalence among patients with organic gastrointestinal conditions such as peptic ulcers or inflammatory bowel disturbance and healthy controls (<20%),1 suggesting a strong association between the irritable bowel syndrome and psychological disorder. Although anxiety, depression, and sexual problems might be the consequence of persistent abdominal symptoms, they are not found to the same extent in patients with organic diseases that also lead to persistent abdominal symptoms.2 The anxiety and depression might explain attendance at the hospital rather than the occurrence of the symptoms,^{3 4} but people attending hospital also have much worse intestinal symptoms than people with the irritable bowel syndrome in the community, and the anxiety almost certainly exacerbates the pain and bowel dysfunction.5