7. Known or suspected organic disorders of the large bowel (i.e. obstruction, carcinoma, or inflammatory bowel disease). Results of a barium enema with flexible sigmoidoscopy or of a colonoscopic examination performed within the last 12 months were needed to rule out organic disorders. A colonoscopic examination or barium enema with flexible sigmoidoscopy performed within the last 3 years was acceptable if the examination was performed for an evaluation of constipation, and there was no history or evidence of weight loss, anaemia, or rectal bleeding, and the patient had 3 consecutively negative stool occult blood tests at screening. Patients with polyps discovered by colonoscopy that were untreated (i.e. by polypectomy) were to be excluded.