Colonic Gallstone Ileus: A Rare Etiology of Large Bowel Obstruction

Large bowel obstruction is a surgical emergency that requires prompt diagnosis and management. It is frequently caused by colon cancer. However, the common benign etiologies include volvulus, hernia, adhesions, and strictures. Imaging studies are essential to establish the diagnosis and identify the etiology. We present the case of a 44-year-old female who presented to the emergency department with abdominal pain and distension for a one-week duration. The pain was associated with decreased bowel motions and vomiting. Her past medical history was significant for diabetes mellitus, dyslipidemia, polycystic ovarian syndrome, and recurrent episodes of biliary colic. Upon examination, she had tachycardia, normal temperature, and normal blood pressure. Abdominal examination revealed a distended abdomen with generalized tenderness and increased intensity of bowel sounds. The laboratory markers were noncontributory. Abdominal computed tomography (CT) scan of the abdomen with intravenous contrast demonstrated the presence of an oval-shaped hypodense intraluminal mass in the sigmoid colon where there was a transition point with proximal colonic dilatation. There was an abnormal communication between the gallbladder and the colon at the hepatic flexure, representing a cholecystocolic fistula tract. This represents a mechanical obstruction of the large bowel due to migrated gallstone through a cholecystocolic fistula tract. The patient was prepared for an emergency laparotomy. The gallstone was removed, and the sigmoid colon was sutured primarily. Resection of the gallbladder was made with the closure of the fistula tract. Following the surgery, the patient reported a resolution of her abdominal pain. Oral feeding was started gradually. After six months of close follow-up, the patient remained asymptomatic with no new complaints. Cholecystocolic fistula is a very rare complication of gallbladder disease. Despite its rarity, surgeons should remember this etiology of large intestinal obstruction when they encounter a patient with gallbladder disease.