A 49-year-old woman arrived at the emergency department after experiencing 12 hours of severe right-sided flank pain accompanied by nausea and vomiting. Her temperature was 38.7°C (101.7°F). She reported no significant past medical history. A CT scan of the abdomen and pelvis was ordered on suspicion of appendicitis. Urinalysis was positive for leukocytes, bacteria, and elevated WBC count.