<prompt> The most common site of intestinal abstruction in gallstone ileus isDuodenumJejunumIleumSigmoid colon  <response>: .GALLSTONE ILEUS is a type of acute intestinal obstruction, often seen in elderly and is due to blockage by a bolus or mass of gallstones which commonly enter the intestine through cholecystoduodenal fistula or rarely through cholecystointestinal or -gastric fistulas .Gallstones in the gallbladder Cholecystitis Suppuration and adhesion over the duodenal wall Communication of gallbladder into the duodenum Gallstones pass into the duodenum forms a bolus Rolling stone gather mass Blocks narrow pa in the ileum. Gallstone ileus ref:SRB;S manual of surgery,ed 3,pg no 594 