We report a case of a 50-year-old man who presented with abdominal pain and shock due to an allergic angioedema of the bowel resulting from the use of a common class of anti-hypertensive medication. After initial stabilization, a computed tomography (CT) scan was performed that documented characteristic findings and saved the patient from an unnecessary laparotomy. Although rare, this etiology of abdominal pain and hypotension should be considered as more and more individuals are taking angiotensin-converting enzyme inhibitors.