Post endoscopic retrograde cholangiopancreatography (ERCP) pancreatitis is a common cause of morbidity for which there is no known pharmacologic prophylaxis. Post-ERCP pancreatitis is thought to be caused by several factors, including intraductal pressure, multiple duct injections with contrast, and neural arc reflexes. Lidocaine is a safe, inexpensive class IV antiarrhythmic that has topical anesthetic effects, inhibits trypsin activity, and may potentially prevent post-ERCP pancreatitis by injection directly into the pancreatic duct at the time of ERCP. Lidocaine has been shown to inhibit phospholipase A2, a key pancreatic enzyme, interrupt local arc reflexes to stop neuronal transmission, and to dampen GI tract mucosal reflexes to prevent high ductal pressure.