Left Lateral Position and Prone Position for Endoscopic Retrograde Cholangiopancreatography

"1. Endoscopic retrograde cholangiopancreatography is started using conventional duodenoscope (TJF 240 or 260V, Olympus Optical Co., Ltd, Tokyo, Japan) in randomly assigned left lateral position or prone position.~2. Selective bile duct cannulation is performed using wire-guided cannulation.~3. In case of difficult cannulation, precut is performed using a needle-knife.~4. After selective cannulation, cholangiogram is obtained using ERCP catheter, and endoscopic sphincterotomy and/or endoscopic papillary balloon dilation is performed."