Gastric outlet obstruction (GOO) can present with nausea, vomiting, and abdominal pain due to a mechanical obstruction. Gallstone ileus represents 4% of cases of GOO. We present the case of GOO due to Bouveret's Syndrome. A 72 year old male was admitted with abdominal distention, pain, nausea, and vomiting for 2 days. Three liters of gastric contents were removed via nasogastric tube(NGT). Computerized tomography of the abdomen showed a markedly distended stomach with an air-fluid filled esophagus, soft tissue change around the duodenum (1st portion) extending to the gallbladder and associated adenopathy with an intrahepatic biliary ductal dilatation. The gallbladder was decompressed. Low-attenuation lesions were noted in the bile duct near the pancreatic head and liver dome. Esophagogastroduodenoscopy (EGD) revealed large amount of food in the stomach, non-bleeding gastric ulcers, and an impacted material in the bulb (that resemble a vegetable) which prevented the passage of different sized scopes (Fig 1). EGD was aborted, and NGT was replaced. Magnetic resonance imaging of the abdomen confirmed a fistulous communication from the gallbladder neck to the proximal duodenum with a 3 cm obstructing stone eroded into the first portion of duodenum (Fig 2). Inflammation resulted in common bile duct narrowing with upstream dilation and hepatic microabscesses. An exploratory laparoscopy was performed. Omental adhesions in the right upper quadrant were lysed. The entire 1st portion of the duodenum and pylorus were embedded onto the inflammatory process rising concern for a large-hole defect in the duodenum if cholecystectomy/fistula repair was done. During laparotomy, repeat EGD did not show a gallstone. The examined duodenum and jejunum were normal except for a 12-mm choledochoduodenal fistula in duodenal bulb. Surgeons extracted a 4.2 x 2.5 x 2.5 cm migrated gallstone from distal ileum. He was discharged on day 4 in stable condition. Bouveret's Syndrome is an unusual cause of GOO mostly seen in elderly patients. A gallstone becomes impacted in the duodenum through a cholecystoduodenal fistula. Despite endoscopic options the majority of patients require surgery which carries a high risk of morbidity and mortality. This case illustrates a common condition (gallstones) presenting atypically which requires a high index of clinical suspicion, early diagnosis is crucial in order to avoid poor outcomes in an already fragile, elderly population.Figure: Gallstone impacted in duodenal bulb.Figure: Figure 2. Fistulous communication from the gallbladder neck to the proximal duodenum.