Selective placement of a guidewire into the bile duct (biliary cannulation) during endoscopic retrograde cholangiopancreatography (ERCP) is necessary for performing therapeutic biliary procedures. The success rate for biliary cannulation by experienced endoscopists during ERCP is approximately 85% with standard cannulation techniques. Inadvertent placement of the guidewire into the pancreatic duct rather than the bile duct often occurs when attempting selective biliary cannulation in technically challenging cases. When this occurs repeatedly, other approaches may be used to facilitate selective biliary cannulation, but there are few prospective studies evaluating the efficacy and safety of these approaches. Here the investigators evaluate two approaches for technically challenging biliary cannulation: one involving maintenance of a wire in the pancreatic duct, followed by repeat attempt at biliary cannulation (double wire technique) and one involving a small incision in the septum adjacent to the pancreas followed by repeat attempt at biliary cannulation (transpancreatic septotomy). This study is a prospective randomized trial comparing the rate of cannulation success, procedure duration and complications following these two approaches.