Review Question - QID 103317

A 12-year-old boy is brought to the emergency department by his mother for evaluation of abdominal pain that has slowly become more noticeable on his right side. He reports associated fevers, chills, and nausea. He denies associated diarrhea. He has no significant medical history and takes no medications. His temperature is 102.2°F (39.0°C), pulse is 110/min, blood pressure is 100/60 mmHg, and respirations are 22/min. On exam, the abdomen is soft with tenderness and rebound in the right lower quadrant. Which of the following is the most appropriate next step in management?