RESUMEN
BACKGROUND: Sigmoid gallstone ileus is a rare complication of cholelithiasis, accounting for 1-4% of all cases of large-bowel obstruction. This is a highly morbid, and often fatal, condition due to its challenging diagnosis and late presentation. CASE PRESENTATION: We report a case of a 90-year-old woman admitted to Emergency Department with abdominal pain and large-bowel obstruction due to a 6 cm gallstone lodged in a diverticulum of the proximal sigmoid colon as a consequence of a cholecysto-colonic fistula. Colonoscopy was deferred due to gallstone size carrying a high possibility of failure. The patient underwent urgent laparotomy with gallstone removal via colotomy. The cholecystocolonic fistula was left untreated. The post-operative course was uneventful; the patient was discharged on 6th post-operative day. CONCLUSION: A multidisciplinary discussion between endoscopists and surgeons is often needed to choose the best therapeutic option, especially in high-risk patients.