Access to the main bile duct is the first step in order to perform a therapeutic maneuver for biliary diseases. Early precut has been shown to ameliorate cannulation success rate, specially in difficult cannulation cases, when compared to guidewire cannulation (which is considered, for most, the standard technique). We aim to perform a randomized clinical trial comparing fistulotomy (F) precut vs guidewire cannulation (CC), as a primary cannulation technique, and compare outcomes between high experienced endoscopists (\> 200 ERCPs\[Endoscopic Retrograde cholangiopancreatography\]) and low experienced endoscopists (\< 200 ERCPs).