An unusual case of subacute small bowel obstruction - Gallstone ileus.

INTRODUCTION AND IMPORTANCE: Gallstone ileus is caused by an impaction of one or more gallstones within the gastrointestinal tract, leading to mechanical intestinal obstruction. It is a rare complication of cholelithiasis leading to the formation of a cholecystoenteric fistula and is associated with high mortality rates. We report a case of atypical subacute small bowel obstruction due to gallstone ileus.

PRESENTATION OF CASE: An 82-year-old man, with previously diagnosed cholelithiasis, presented with abdominal pain and vomiting for nine days. The contracted gallbladder with distended bowel loops was visualized on abdominal ultrasound. Computed tomography of the abdomen and pelvis revealed dilated loops of the small intestine with a gallstone in the proximal ileum, causing intestinal obstruction with pneumobilia, suggesting gallstone ileus with cholecystoduodenal fistula. The patient underwent an emergency laparotomy and enterolithotomy to remove the impacting gallstone. The cholecystoduodenal fistula was left undisturbed due to the significant risk of duodenal injury. The patient had an uneventful postoperative recovery.

CONCLUSION: Gallstone ileus almost always requires surgical management. However, performing an interval biliary surgery is based on the clinical judgment of the surgeon. In our case, the patient's clinical status determined the treatment in which an enterotomy with stone extraction alone was largely sufficient, and has supported the literature. Gallstone ileus is an important differential diagnosis in elderly patients with gallstone disease, untreated or undiagnosed, presenting with features of small bowel obstruction.