INTRODUCTION: Most gallstone-induced pancreatitis is mild, resolves spontaneously, does not require endoscopic retrograde cholangiography (ERC), and is treated by pre-discharge cholecystectomy. Conversely, severe, necrotizing gallstone-induced pancreatitis is associated with organ failure and mandates ERC. A subset of patients exists with moderately-severe pancreatitis, not associated with organ failure, but with substantial pancreatic and peripancreatic inflammation that renders pre-discharge laparoscopic cholecystectomy (LC) prone to complication. In this patient group, ERC with endoscopic sphincterotomy (ES) may prevent recurrent pancreatitis, permit delayed LC, and decrease overall risks. This hypothesis has not been studied, however.METHODS:The medical records of all patients with pancreatitis undergoing cholecystectomy from 1999-2004 were reviewed and data regarding demographics, clinical course, etiology of pancreatitis, operative and endoscopic interventions and outcome were extracted. Moderately-severe gallstone-induced pancreatitis was defined as pancreatitis without organ failure but extensive local inflammation that likely precludes successful LC.RESULTS:Thirty patients (16 female) with moderately-severe gallstone pancreatitis underwent ERC+ES and were discharged from the hospital prior to cholecystectomy. Mean interval between ES and cholecystectomy was 102 days (28-462). Cholecystectomy was performed laparoscopically in 25 patients (83%), open in 3 (10%), and converted to open in 2 patients (6.7%). No patient had a pseudocyst that required drainage, but two patients (6.7%) required a pancreatic necrosectomy at the time of cholecystectomy. Interval complications requiring hospital admission developed in 7 patients (23%) including cholangitis (2), pneumonia (2), abdominal pain (2), infected pancreatic fluid collection (1), and nausea and vomiting (1). No patient developed interval pancreatitis or choledocholithiasis after ERC+ES. Median length of stay after cholecystectomy was 1 day (1-26).  CONCLUSION:Recurrent biliary pancreatitis in patients with moderately severe gallstone pancreatitis is nil after ERC+ES, supporting a protective effect of ES. Hospital discharge of this patient population permits interval cholecystectomy, but close follow-up is necessary in these potentially ill patients.