Sixty per cent of the patients referred to two gastroenterological clinics and diagnosed as suffering from the irritable bowel syndrome (IBS), were found to have significant psychoneurotic morbidity on the basis of the General Health Questionnaire. A double-blind, completely randomised, placebo controlled comparison of treatment with a combined anxiolytic/antidepressant (Motipress) found a significantly better effect of Motipress than placebo on diarrhoea and abdominal pain. Detailed analysis of the results suggests that there is no direct relationship between psychoneurotic illness and IBS, but the presence of the former has an adverse effect on the short-term outcome of the bowel disorder.