This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Gall Bladder & Bile Ducts, Subject name: Surgery
Most common site of gall stone impaction in Cholecysto Intestinal fistula is 
Select and explain. 
A. DJ junction, B. Proximal to ileo-cecal junction, C. Distal to ileo-cecal junction, D. Colon
B: Proximal to ileo-cecal junction
Answer: B: Proximal to ileo-cecal junction 
Explanation: Ans. (b) Proximal to ileo cecal junctionRef: Sabiston 20th edition Page 1506Gallstone ileus:* MC site of obstruction is terminal ileum* Intermittent obstruction is seen* Pneumobilia is seen* 10% have multiple stones in small intestine