Rectal Indomethacin in the Prevention of Post-endoscopic Retrograde Cholangiopancreatography (ERCP) Pancreatitis in High Risk Patients

Inclusion Criteria: Included patients are those undergoing ERCP and have one of the following: 1. Clinical suspicion of sphincter of Oddi dysfunction 2. History of post-ERCP pancreatitis (at least one episode) 3. Pancreatic sphincterotomy 4. Pre-cut (access) sphincterotomy 5. \> 8 cannulation attempts 6. Pneumatic dilation of intact biliary sphincter 7. Ampullectomy or at least 2 of the following: 1. Age \< 50 years old \& female gender 2. History of recurrent pancreatitis (at least 2 episodes) 3. ≥3 pancreatic injections, with at least one injection to tail 4. Pancreatic acinarization 5. Pancreatic brush cytology Exclusion Criteria: 1. Unwillingness or inability to consent for the study 2. Age \< 18 years 3. Intrauterine pregnancy 4. Breast feeding mother 5. Standard contraindications to ERCP 6. Allergy to Aspirin or NSAIDs 7. Renal failure (Cr \> 1.4) 8. Active or recent (within 4 weeks) gastrointestinal hemorrhage 9. Acute pancreatitis (lipase peak) within 72 hours 10. Known chronic calcific pancreatitis 11. Pancreatic head malignancy 12. Procedure performed on major papilla/ventral panc duct in pt with pancreas divisum (no manipulation of minor papilla) 13. ERCP for biliary stent removal or exchange without anticipated pancreatogram 14. Subjects with prior biliary sphincterotomy now scheduled for repeat biliary therapy without anticipated pancreatogram 15. Anticipated inability to follow protocol 16. Endoscopist discretion: low risk (\<10%) of post-ERCP pancreatitis