Background : Gallstone ileus, an infrequent complication arising from cholelithiasis, resulted in mechanical small bowel obstruction. The mortality rate is approximately0 15-18% but mostly due to co-morbid conditions in the patient population. Treatment includes the surgical removal of the gallstone in the bowel and resolution of the underlying issues within the biliary tract that causes gallstone. We present a rare case of gallstone disease.

Methods : Case: A 66-year-old female, with no medical history, presented to the emergency room with a 10-day history of symptoms, including nausea, bilious vomiting, constipation, and gradual oliguria. She previously had laparoscopic cholecystectomy at another center. During the physical examination, she showed no signs of jaundice or abdominal tenderness. Vital signs were stable. Initial laboratory results indicated an elevated liver function test, with a total bilirubin level of 1.8 mg/dL. White blood cell count and C-reactive protein were also elevated at 16,680 cells/uL and 184.9 mg/L, respectively. Amylase and lipase were within normal limits. The abdominal computed tomography (CT) revealed fusiform dilatation of the common bile duct (CBD) with a diameter of 4.1cm, accompanied by a large 3.5cm stone. An underlying choledochal cyst was suspected. Mild dilatation of the jejunum was observed due to a 3.3cm radiolucent stone in the jejunum. Chest CT revealed bronchopneumonia, although she exhibited no pulmonary symptoms. Initially, gastric decompression was achieved by a nasogastric tube, and fluid therapy was done. Endoscopic retrograde cholangiopancreatography (ERCP) was performed, revealing a large CBD stone with a choledochoduodenal fistula. The CBD stone could not be successfully removed via ERCP. She underwent bile duct resection to remove the CBD stone along with hepaticojejunostomy and jejunostomy to remove the gallstone along with primary repair. The operation time was 160 minutes with an estimated blood loss of 400ml. The operation was uneventful.

Results : Following the surgery, due to pneumonia and a urinary tract infection along with a compromised general condition, she was discharged on postoperative 30 days.

Conclusions : Gallstone ileus usually results from a large gallstone passing through cholecystoenteric fistula. However, in this case, the emergence of gallstone ileus was from the choledochoduodenal fistula. She might have the underlying choledochal cyst and the CBD stone causing erosion of the CBD wall and resulting in the choledochoduodenal fistula.