Which is the most common location of Gallstone Ileus?

Ans: c. (ileum)Ref: Sabiston, 18lhed. pg. 1572According to Sabiston, "Passage of a stone through a spontaneous biliary enteric fistula leading to a mechanical bowel obstruction is known as gallstone ileus. Most (75%) of these fistulas develop between the gallbladder and duodenum. In patients older that 70 years gallstone ileus may account for as many as 25% of cases of intestinal obstruction. It is called as tumbling obstruction as the impacted stone temporarily obstructs the bowel lumen and then dislodges and moves distally. The most common site of obstruction is the terminal ileum because of its narrow lumen"Thus the most common site of obstruction is the terminal ileum.Most common site of biliary- enteric fistula leading to gall stone ileus is duodenum.Management consists of relieving the obstruction by removing the gallstone through a incision on the bowel at a proximal healthy site.Gall stones : Gall stones can be classified by their cholesterol content into cholesterol stones and pigment stones.Incidence of cholesterol stones- 70 - 80%.Incidence of black pigment stone- 20- 30%.The standard diagnostic investigation for gallstones ultrasound abdomen.Pigment stones are dark due to deposition of calciumbilirubinate.Stone associated with hemolytic state- black pigment stones.Stone occurring as primary bile duct stone - brovm pigment stones.Choledochal stones (stones in the bile duct) can lead to acutecholangitis manifested by Charcot's triad.lt may be severe, leading to Reynold's pentad.