Review Question - QID 103330

A 46-year-old man with no significant past medical history presents to the emergency department with a few days of worsening abdominal pain and fever. He states that earlier in the week, he began experiencing nausea before the sharp pain began in his umbilicus and localized to his left lower abdomen. He has been able to tolerate liquid intake, but does not have much appetite for more substantial food. His vital signs show a temperature of 38.7°C (101.7°F), blood pressure of 127/84 mmHg, pulse of 100/min, respirations 14/min, and oxygen saturation of 98% on room air. Physical exam is notable for left lower quadrant tenderness and abdominal distension, but no involuntary guarding or rigidity. A complete blood count reveals leukocytosis with left shift. CT of the abdomen and pelvis is shown in Figure A. Which of the following is the most appropriate next step in management for this patient?