John, aged 47, had sudden onset of midabdominal pain and nausea. Examination at a local emergency department (ED) revealed a diffusely tender abdomen without rebound or guarding. The ED physician sent ...

A 19-year-old man with a history of laparoscopic appendectomy for perforated appendicitis presented with a five-day history of vague periumbilical pain that had localized to the right lower quadrant.