In gallstone ileus, obstruction is seen at

Gallstone ileus Passge of stone through a spontaneous biliary-enteric fistula leading to a mechanical bowel obstruction Most common site of fistula : Between the gallbladder and duodenum Clinical features Rigler's triad - Classic pain abdominal film triad of small bowel obstruction, pneunobilia & ectopic gallstone is considered pathognomic Most common site of obstruction is ileum(60%); jejunum (15%); colon(5%> sigmoid colon) & duodenum (5%) Ref:1506-1507