All patients will be observed for 4 hours following ERCP which is part of the routine clinical practice following ERCP. Patients with minimal pain will be discharged after a 4-hour period of observation. All patients will have baseline serum amylase levels which will be repeated 4 hours after the ERCP has been completed. Patients with significant abdominal pain following ERCP will be hospitalized overnight and evaluated for post-ERCP pancreatitis with monitoring of vital signs, urinary output and serum amylase levels the following morning. Patients with ongoing symptoms at 48 hours and later will undergo imaging with either abdominal ultrasonography or CT scanning. This also represents current standard clinical practice.