The goal of this clinical trial is to compare rectal indomethacin alone versus combined pancreatic duct stenting and rectal indomethacin in prevention of post ERCP pancreatitis. The main question it aims to answer is: whether rectal indomethacin alone is superior to combination of pancreatic duct stenting and rectal indomethacin in prevention of post ERCP pancreatitis Participants will be patients who give consent to the study and who are required to undergo ERCP as part of their standard care.

If there is a comparison group: Researchers will compare [rectal indomethacin alone versus combined pancreatic duct stenting and rectal indomethacin in prevention of post ERCP pancreatitis.] to see if [whether rectal indomethacin alone is superior to combination of pancreatic duct stenting and rectal indomethacin in prevention of post ERCP pancreatitis].

Inclusion Criteria:

1. Suspected sphincter of Oddi dysfunction

2. History of post ERCP Pancreatitis

3. Pancreatic instrumentation or sphincterotomy.

4. Precut sphincteroyomy

5. Difficult cannulation defined by more than 5 cannulation attempts

6. The use of double wire technique in bile duct access

7. At least 2 of the followings including

   1. Female age < 50 year
   2. 3 pancreatogram
   3. Acinarization (Contrast injection to tail of pancreas
   4. Normal serum bilirubin
   5. Guidewire to the tail of pancreas or secondary branches

Exclusion Criteria:

1. Patient planned for pancreatic stenting
2. Without informed consent
3. Age < 18 years
4. Pregnant women
5. Lactating women
6. Patient with altered anatomy
7. Contraindications to the use of NSAIDS
8. Renal failure
9. Ongoing or recent hospitalisation for acute pancreatitis
10. Allergy to aspirin or NSAIDs
11. known chronic calcific pancreatitis -