A lady presented with 3 day history of epigastric pain radiating to back. Serum amylase levels were observed to be normal while USG abdomen reveals gall bladder stones and an enlarged pancreas. CT scan was done which clinched the diagnosis. Which of the following is most likely diagnosis

Common Causes of Acute pancreatitis Gallstones(including microlithiasis) Alcohol(acute and chronic alcoholism) Hyperiglyceridaemia ERCP, Especially after biliary manometry Drugs- Azathioprine, 6-Mercaptopurine, sulfonamides, estrogens, tetracycline, valproic acid, anti-HIV medication, 5-aminosalicylic acid Trauma(especially blunt abdominal trauma) Post operative (abdominal and non abdominal operations) Pain is the major symptom. Pain- may vary from mild discomfo to severe constant and incapacitating distress. Pain which is steady and boring in character is located in the epigastrium and peri umbilical region and may radiate to back, chest, flanks and lower abdomen. Nausea, vomiting and abdominal distension due to gastric and intestinal hypomotility and chemical peritonitis are also frequent complaints Ref: Harrison's principles of internal medicine 19th edition Pgno: 2091, 2092