['Endoscopic sphincterotomy (ES) may facilitate insertion of self expandable metal stent (SEMS) and also help avert the development of pancreatitis from stent-related occlusion of the pancreatic duct. On the other hand, ES is also independently associated with pancreatitis, bleeding, and perforation. We evaluated whether ES before SEMS placement was associated with a greater likelihood of stent migration and other complications in patients with malignant obstruction of the distal common bile duct.', 'Seventy-four patients with unresectable distal bile duct obstruction were prospectively randomized to biliary stenting following ES (group 1) and without ES (group 2). Main outcome measures included overall procedure complications rates including stent migration, stent occlusion, oxygen desaturation, bleeding, perforation, and pancreatitis.', 'Covered SEMS were successfully deployed in all patients in both groups. Stent migration occurred in 6 patients (16%) in group 1 and 1 patient (3%) in group 2, P=0.075. Overall, complications occurred in 18 patients in group 1 and 4 patients in group 2, P=0.006. There was no pancreatitis in either group.'] Is endoscopic sphincterotomy before deployment of covered metal stent associated with greater complication rate : a prospective randomized control trial?