A Tough Nut to Crack: Navigating a Rare Case of Bouveret Syndrome.

Bouveret syndrome, a rare complication of cholelithiasis (1%-3%), leads to high mortality (12%-30%). It occurs when a gallstone passes through a cholecystoduodenal fistula, causing gastric outlet obstruction. We report a 66-year-old woman with abdominal pain, nausea, and vomiting. Imaging showed acute cholecystitis, pneumobilia, cholecystoduodenal fistula, and a 5-cm gallstone obstructing the gastric outlet. Initial treatment with antibiotics and endoscopic lithotripsy relieved the obstruction but did not remove the entire stone. Surgery with open gastrotomy successfully extracted the stones, and follow-up confirmed fistula closure. This case highlights the need for early diagnosis and a multidisciplinary treatment approach.