A young man with fever, chills, and abdominal pain

A 28-year-old African-American man presented with constant, sometimes sharp, abdominal pain that was partially relieved by lying down. The pain had begun five days earlier, starting in his back and radiating to his epigastrium. He had had fever, chills, nausea, and loss of appetite for about two weeks, and constipation for four days. He had not had heartburn, bleeding, dysuria, or recent trauma.