Question: A 70-year-old woman who was visiting our city presented to the emergency department with a 24-hour history of nausea, voluminous, recurrent vomiting, and epigastric pain. Medical history disclosed gastroesophageal reflux disease, osteoporosis, and chronic cognitive impairment. There was no antecedent of trauma or surgical interventions. She was taking omeprazole and raloxifene hydrochloride as regular medications. At presentation, vital signs were unexceptional and she did not look seriously ill. On examination her abdomen was soft, nontender, and without palpable masses. Laboratory testing was notable for a white blood cell count of 11,300/mm3, erythrocyte sedimentation rate and renal function parameters being within normal limits. Chest radiography displayed no subdiaphragmatic free air but a plain abdominal x-ray demonstrated a significant abnormality (Figure A). What is the diagnosis? Look on page 1223 for the answer and see the Gastroenterology web site () for more information on submitting your favorite image to Clinical Challenges and Images in GI. Plain abdominal x-ray at admission revealed air in the theoretical localization of the biliary tree and paucity of intestinal gas. In view of the history and these radiographic findings, a computed tomography (CT) was requested. Abdominal CT (Figure B; medial view; Figure C, axial view) showed the classic Rigler’s triad of pneumobilia (small black arrows), ectopic gallstone (white arrow), and bowel obstruction, which is specific for gallstone ileus. A cholecystoduodenal fistula (large black arrow), gastric distension, and pericholecystic inflammatory changes could also be appreciated. Because the gallstone was impacted into the second part of the duodenum, a diagnosis of Bouveret’s syndrome was established. After early conservative management, the patient’s relatives asked us for permission to transfer her to their reference center. Once there and while discussing about the most appropriate therapeutic procedure to be performed, the gallstone (4 cm in size) was surprisingly eliminated with feces (Figure D) and she was discharged asymptomatic without need of surgical intervention. Throughout the following year, she has remained symptom free. Leon Bouveret described in 1896 the two first patients with gastric outlet obstruction caused by impacted gallstones into the duodenum after passage through a cholecystoduodenal fistula.1Bouveret L. Stenose du pylore adherent à la vesicule.Rev Med (Paris). 1896; 16: 1-16Google Scholar Risks factors for this uncommon form of gallstone ileus are female sex, advanced age (>60 years), long history of cholelithiasis, recurrent cholecystitis, and large size of the calculi.2Mavroeidis V.K. Matthioudakis D.I. Economou N.K. et al.Bouveret syndrome—the rarest variant of gallstone ileus: a case report and literature review.Case Rep Surgery. 2013; 2013: 839370PubMed Google Scholar, 3Cappell M.S. Davis M. Characterization of Bouveret’s syndrome: a comprehensive review of 128 cases.Am J Gastroenterol. 2006; 101: 2139-2146Crossref PubMed Scopus (124) Google Scholar In this context, minimally invasive treatment, such as endoscopic retrieval or lithotripsy, has a rather low success rate.3Cappell M.S. Davis M. Characterization of Bouveret’s syndrome: a comprehensive review of 128 cases.Am J Gastroenterol. 2006; 101: 2139-2146Crossref PubMed Scopus (124) Google Scholar Although enterolithotomy or gastrostomy, with or without cholecystectomy and fistula repair, are the most common therapeutic approaches, spontaneous resolution can exceptionally occur.3Cappell M.S. Davis M. Characterization of Bouveret’s syndrome: a comprehensive review of 128 cases.Am J Gastroenterol. 2006; 101: 2139-2146Crossref PubMed Scopus (124) Google Scholar