A retrospective analysis was made of 114 new patients attending a gastroenterology clinic, in whom the initial clinical diagnosis was irritable bowel syndrome. Barium enemas were performed in 84 patients (74%), 15 of whom were found to have significant other disease. In each case this would have been suspected from the routine haematological and biochemical screening tests. It is suggested that, in the investigation of patients under 50 years of age presenting to a gastroenterology clinic with a typical history of irritable bowel syndrome, a barium enema should only be performed if the clinical examination, sigmoidoscopy, rectal biopsy or routine blood tests are abnormal. This policy would reduce substantially the number of normal barium enemas performed.