Pressure measurements from biliary and pancreatic segments of sphincter of Oddi. Comparison between patients with functional abdominal pain, biliary, or pancreatic disease. Using a minimally compliant infusion system and a triple-lumen pressure recording catheter, we obtained endoscopic manometric measurements from both the common bile duct and pancreatic duct segments of the sphincter of Oddi (SO) in 58 patients. Fifteen patients (ages 27-69) had the diagnosis of functional abdominal pain, 19 patients (ages 30-76) had partial biliary obstruction, and 24 patients (ages 15-80) had idiopathic acute recurrent pancreatitis. Resting ductal pressure was similar in the common bile duct and pancreatic duct in all patient groups. In the group with functional pain, basal SO pressure was similar, whether obtained from the common bile duct or pancreatic duct sphincteric segment. Eight of 19 patients with partial biliary obstruction had elevated basal SO pressure. Five of these eight patients had elevated basal SO pressure confined exclusively to the common bile duct segment of the sphincter, while three patients had elevated basal SO in both segments. Conversely seven of 24 patients with acute recurrent pancreatitis had an elevated basal SO pressure, with five patients having pressure elevation only in the pancreatic duct segment while two patients had abnormal basal SO pressure in both segments. We conclude that selective cannulation of the common bile duct and/or the pancreatic duct during manometric study of the SO is necessary in order to diagnose segmental SO dysfunction responsible for partial biliary obstruction or episodes of acute recurrent pancreatitis. 