Diagnosis of a perforated ulcer on an excluded stomach after bypass surgery.

While the clinical and radiological symptoms of peptic ulcer perforation in cases of so-called "normal" anatomy are well established, this is less so in cases where the stomach has been excluded, as after gastric bypass. Indeed, in these cases, the initial clinical signs are often subtle and nonspecific. So, too, as are the laboratory findings, which often, in the initial phase, do not reveal an inflammatory syndrome and sometimes present with a misleading elevation of serum lipase. Also, pneumoperitoneum is often absent on imaging. Thus, after gastric bypass and when there is a history of Helicobacter pylori infection, active smoking, or NSAID use, the appearance of intense abdominal pain with abdominal tenderness and guarding, and the presence of peritoneal effusion (possibly bilious), despite the absence of pneumoperitoneum, should raise the suspicion of ulcer perforation in an excluded stomach, which requires urgent exploratory laparoscopy to avoid treatment delay.