Mechanical Small-Bowel Obstruction Caused by Gallstone Ileus: A Case Report

Abstract

Introduction Gallstone ileus is a rare complication of gallstone disease caused by passage of a large gallstone through a biliary–enteric fistula, leading to mechanical small bowel obstruction (SBO). Because symptoms are often non-specific, diagnosis is frequently delayed [1]. This report describes a 53-year-old woman who presented with acute abdominal symptoms and was found to have gallstone ileus secondary to a cholecysto-duodenal fistula. Case Presentation A 53-year-old female arrived at Kaunas Clinics Emergency Department with severe (7 VAS) generalised abdominal pain, bloating, nausea, vomiting and inability to pass stools or gas for five days. Examination revealed a distended, diffusely tender abdomen with negative rebound tenderness. Ultrasound showed cholelithiasis and dilated intrahepatic bile ducts. Contrastenhanced CT revealed a small, non-contractile gallbladder surrounded by air and inflamed adipose tissue. A cholecysto-duodenal fistula was identified, and a 3×2×4 cm ectopic partially calcified gallstone was visualised impacted in the terminal ileum, causing mechanical SBO with dilated jejunal loops (3,2 cm) above the obstruction. The patient was admitted to the Department of Surgery for definitive treatment where operative findings confirmed CT results. Discussion Gallstone ileus accounts for 1–4% of mechanical bowel obstruction and predominantly affects elderly women [2]. Chronic cholecystitis may lead to biliary-enteric fistula formation, allowing gallstones to migrate into the bowel and lodge most commonly in the ileum [3]. Symptoms include abdominal pain, distension, vomiting and constipation [4]. CT is the diagnostic gold standard, demonstrating pneumobilia, ectopic gallstone and obstruction (Rigler's triad) as well as abnormal gallbladder (fluid accumulation within the wall, presence of air-fluid level) [5]. Treatment requires surgical removal of the obstructing stone; options include enterolithotomy alone, single-stage surgery with cholecystectomy and fistula repair, or staged repair depending on patient stability [6]. Conclusions Gallstone ileus should be considered in patients with SBO and concurrent biliary findings. Identification of characteristic CT findings, particularly Rigler’s triad and a biliary-enteric fistula, enables timely diagnosis and surgical planning, thereby reducing morbidity.