This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Surgery
[{'content': 'Internal fistula is MOST commonly found between gallbladder and: \nSelect and explain. \nA. Colon, B. Duodenum 1st pat, C. Jejunum, D. Transverse colon', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Biliary fistula is a complication of gallstone (90% of biliary fistulas are due to gallstone). The inflamed gallbladder becomes adherent to adjacent stomach, duodenum, colon and necrosis develops at the site leading to the development of fistulas. Most common site of fistula is the duodenum. Colon is the 2nd most common siteof fistula. Ref: Hamilton Bailey 10/e, Page 432.', 'role': 'assistant'}]