Seventy-three highly selected patients (35 type II, 38 type III) with intractable biliary-type pain were studied with biliary manometry after a baseline endoscopic retrograde cholangiopancreatography was normal or showed only duct dilatation. No differences between the two groups were noted in regard to baseline sphincter hypertension (60% versus 55%), improvement after endoscopic sphincterotomy at mean follow-up of 3 years, or post-procedure pancreatitis rates (15% versus 16%). Although not statistically significant, a tendency for patients with bile ducts > or = 12 mm to have sustained clinical improvement after sphincterotomy was noted in comparison with patients having ducts < 12 mm; an inverse correlation between improvement in symptoms and presence of an intact gallbladder at baseline was also seen. The authors suggest that the current classification, which divides patients with recurrent right upper quadrant pain into types I, II, and III, is inadequate to define either incidence of sphincter of Oddi dysfunction or subsequent response to endoscopic sphincterotomy.