For 3 days, a 69-year-old man had had intermittent colicky pain on the right side of the abdomen, loose bowel movements, and a low-grade fever. Examination disclosed a mildly tender, palpable, diffuse mass in the right upper quadrant and hyperactive bowel sounds. The patient's stool was positive for occult blood, and a complete blood cell count showed a low hemoglobin level and a slightly elevated white blood cell count.