Marginal ulcers are a late complication of gastric bypass surgery. A marginal ulcer is a term for ulcers that develop at the margins of a gastrojejunostomy, primarily on the jejunal side. A perforated ulcer involves the entire thickness of an organ, creating an opening on both surfaces. We will present an intriguing case of a 59-year-old Caucasian female who arrived at the emergency department with diffused chest and abdominal pain that began in her left shoulder and went down to the right lower quadrant area. The patient was in visible pain with restlessness, and her abdomen was moderately distended. The computed tomography (CT) showed possible perforation in the gastric bypass surgery area, but the results were inconclusive. The patient had laparoscopic cholecystectomy ten days prior, and the pain began right after surgery. The patient underwent an open abdominal exploratory surgery, with the closure of the perforated marginal ulcer. The fact that the patient had undergone another surgery and had pain immediately afterward also obscured the diagnosis. This case shows the rare presentation of the patientäs diverse signs and symptoms and inconclusive reports that led to the open abdominal exploratory surgery that finally confirmed the diagnosis. This case highlights the importance of a thorough past medical history, including surgical history. The past surgical history led the team to zone in on the gastric bypass area, leading to an accurate differential diagnosis.