Because previous studies had found no difference, and one recent study even reported a higher incidence of PEP in treatment arm

This multicentre randomised controlled trial included patients aged >18 years with an indication for ERCP and naive major papilla. All patients received 100 mg of rectal indomethacin and 10 ml of either sterile water or a 1:10,000 epinephrine dilution. Patients were asked about PEP symptoms via telephone 24 hours and 7 days after the procedure.

This multicentre randomised placebo-controlled trial was conducted in two hospitals in Mexico: the National Institute of Medical Sciences and Nutrition "Salvador Zubirán" (INCMNSZ) in Mexico City, and Bernardette Hospital in Jalisco. The study was approved by both institutional review boards. All patients provided written informed consent.

All patients were given a dose of rectal indomethacin (100 mg) at the beginning of the ERCP. Depending on the experimental group, either 10 ml of sterile water or 10 ml of a 1:10,000 epinephrine dilution (0.1 mg/ml) was sprayed on the ampulla through a biliary balloon or a sphincterotome, avoiding any direct contact with the papilla during irrigation at the end of the procedure.

After the procedure, patients were monitored in the recovery room for 2 hours and then discharged. Symptoms of acute pancreatitis or any other complication were interrogated at baseline while in the recovery room, and then by telephone 24 hours and 7 days after the procedure. Serum levels of pancreatic enzymes were determined only if the patient developed abdominal pain after ERCP.

Inclusion Criteria:

• Age 18 years or older
• Patient with an indication for endoscopic retrograde cholangiopancreatography
• Patient without prior endoscopic retrograde cholangiopancreatography
• Patient who accept contact by telephone

Exclusion Criteria:

• Previous sphincterotomy
• Allergy to epinephrine or indomethacin
• NSAIDs use in the prior week
• Pancreatic cancer located in the head
• Chronic pancreatitis
• Renal failure (Cr >1.4 mg / dl)
• Indication for endotracheal intubation independent of endoscopic retrograde cholangiopancreatography
• Biliodigestive derivation
• Pregnant patients

As the two solutions are colourless, the endoscopist, nurse and patient were all blinded to the intervention. Investigators who participated in the evaluation of post-ERCP complications were also blinded to group allocation.