We describe an afferent loop obstruction in a patient who had a subtotal gastrectomy with Roux-en Y gastrojejunostomy for postvagotomy syndrome. The clinical presentation and initial studies suggested acute pancreatitis. A computed tomography scan showed a small bowel obstruction distal to the jejunojejunal anastomosis. The patient was taken to the operating room for an exploratory laparotomy, lysis of adhesions, and closure of her jejunostomy. Surgery was successful at resolving her obstruction. In any Roux-en-Y gastric reconstruction or gastric bypass patient presenting to the emergency department with abdominal pain and elevated transamines or pancreatic enzymes, a small bowel obstruction must be considered. Additional imaging with a computed tomography scan is advocated, as well as surgical consultation.