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
FALSE about Gallstone ileus: 
Select and explain. 
A. 90% patients give history of biliary disease, B. Causes 1% of all SBO; around 25% cases in >70 years, C. Tumbling obstruction, D. Fistula is mostly formed between duodenum and gallbladder
A: 90% patients give history of biliary disease
Answer: A: 90% patients give history of biliary disease 
Explanation: Ans. (a) 90% patients give history of biliary disease* PREVIOUS h/o of gall stone related symptoms is seen only in 50% cases.* Gall stone Ileus constitutes only 1% of etiology of all Small bowel obstructions (also <1% of gallstone cases get this complication).* In old age >70 years- 25% cases are due to Gall stone ileus