Biliopancreatic limb obstruction secondary to 9 cm gallstone nearly two decades following open Roux-en-Y gastric bypass and cholecystectomy: a rare and challenging case.

Gallstone ileus is a rare complication of chronic cholelithiasis and an exceedingly uncommon cause of bowel obstruction following Roux-en-Y gastric bypass (RYGB), particularly after cholecystectomy. We report the first known case of a large gallstone causing obstruction of the biliopancreatic limb in an 80-year-old woman with prior RYGB, cholecystectomy, and choledochoduodenostomy. She underwent successful open enterolithotomy with stone extraction. This case highlights the diagnostic and technical challenges posed by altered post-RYGB anatomy and emphasizes the importance of maintaining a high index of suspicion in similar presentations. Early recognition and individualized operative management are critical to achieving favorable outcomes in this rare but potentially life-threatening condition.