Gallstone ileus with sigmoid impaction through a cholecystocolic fistula: a case report.

Gallstone ileus is a rare cause of bowel obstruction. Colonic impaction, especially in the sigmoid colon, is extremely uncommon and often associated with diverticulosis or structural abnormalities. An 81-year-old woman presented with 2 weeks of abdominal pain, bloating, nausea, and vomiting. A computed tomography (CT) scan revealed a 6.2 cm gallstone in the sigmoid colon with pneumobilia and a cholecystocolonic fistula. After unsuccessful colonoscopic extraction, she underwent laparoscopic enterolithotomy with segmental sigmoid resection. She recovered without complications and remained symptom-free at her 6-week follow-up. Colonic gallstone ileus is rare and should be suspected in elderly women with obstruction and pneumobilia. A CT scan is the diagnostic gold standard. While endoscopy may work for small stones, surgery is usually required. Enterolithotomy with or without resection remains the safest approach in frail patients.