A lack of pancreatic duct compliance and decreased duodenal filling on secretin-stimulated magnetic resonance cholangiopancreatography (s-MRCP) has been noted in patients with chronic pancreatitis. Whether endoscopic sphincterotomy can affect pancreatic duct compliance and duodenal filling on diagnostic s-MRCP is unknown. A retrospective review of patients referred to the authors' clinic from December 2006 to December 2007 was performed. Those patients with no evidence of chronic pancreatitis who underwent s-MRCP were studied. Findings on s-MRCP were analyzed, specifically noting change in pancreatic duct diameter size from baseline to maximum dilation and duodenal filling after secretin administration (0.2 microg/kg intravenous dose of human secretin). Of the 34 patients studied, 12 underwent endoscopic sphincterotomy, and 22 had intact sphincters of Oddi. In the sphincterotomy group, there was a mean change of 0.2 cm (range, 0.0-0.4 cm), while in the nonsphincterotomy group, the mean change was 0.9 cm (range, 0.3-2.0 cm) after secretin administration. The difference was significant (P < .005). Endoscopic sphincterotomy significantly decreases pancreatic duct dilation in response to secretin on s-MRCP. However, further studies are required to determine the effect sphincterotomy has on the amount of duodenal filling and the rate at which duodenal filling occurs.