Post-endoscopic retrograde cholangiopancreatography pancreatitis caused by papillary large-balloon dilation of incidental intrapapillary fistula in Roux-en-Y patients: lesson from a case.

Endoscopic papillary large-balloon dilation (EPLBD) has been popular worldwide for difficult stones. At the primary stage, EPLBD is done immediately after endoscopic sphincterotomy (ES) or after previous ES. Recently, several endoscopists have reported the feasibility and safety of EPLBD without ES and post-endoscopic retrograde cholangiopancreatography pancreatitis (PEP) as adverse events. Herein, we encountered a case of PEP in which EPLBD was carried out through a spontaneous fistula in the papillary roof, although there was no manipulation of the pancreatic duct. We learned a lesson from the present case in which possible PEP might occur during the procedure of EPLBD without ES.