A 30-year-old woman is recovering from an open cholecystectomy in the hospital. On the second postoperative day, she begins to complain of cramping abdominal pain without vomiting. She has no past medical or surgical history, and her postoperative course has been unremarkable. She is receiving oral hydrocodone for pain and is on a clear liquid diet. She has a temperature of 99.5 ° F, blood pressure is 128/ 84 mmHg, and pulse is 82/ min. Her physical exam is significant for absent bowel sounds, a mildly distended abdomen with mild diffuse tenderness without rebound or guarding. Which of the following would most benefit her abdominal findings?
(A) Encouraging ambulation
(B) Placement of a nasogastric tube
(C) Neostigmine
(D) Conversion of hydrocodone to a nonsteroidal anti-inflammatory drug
(E) Return to the operating room for exploration