A double-blind study was carried out in 18 patients with biliary and pancreatic disease to assess the use of pinaverium bromide in premedication for endoscopic retrograde cholangio-pancreatography and its effects on motor activity of the sphincter of Oddi. Patients were divided at random into three groups. One group received 100 mg pinaverium bromide twice daily for 3 days before and then 100 mg 1 hour before the examination, the second group received placebo, and the third had no medication. All patients received 10 to 20 mg diazepam intravenously 10 minutes before endoscopy. Assessments were made of the transit time of various endoscopic phases and patients' tolerance of the procedure. The effects of treatment on the sphincter of Oddi were estimated by means of endoscopic manometry. The results showed that pinaverium bromide allowed transit time reduction in endoscopic procedure, a greater tolerance on the part of the patient and marked reduction in the amplitude and duration of the phasic activity of the sphincter.