BACKGROUND: Postoperative ileus remains a common condition that prolongs hospitalization and increases the cost of surgical therapy. Ketorolac, a potent nonsteriodal antiinflammatory drug, has been known to prevent small bowel ileus in a rodent model. Therefore, we compared the effect of intravenous patient-controlled analgesia (iv PCA) with or without ketorolac. METHODS: Fifty-four patients undergoing gynecologic surgery were assigned in a double-blind manner into one of three groups (n = 18). Pain control was achieved using meperidine 600 mg only (group M), meperidine 300 mg-ketorolac 150 mg (group MK) or butorphanol 10 mg-ketorolac 150 mg (group BK) during the 48 hours following surgery. It was designed as loading (30 mg), continuous infusion (9.6 mg/hr), PCA dose (9.6 mg) and lockout interval (15 min) for group M and as loading (30 mg of ketorolac), continuous infusion (2 ml/hr), PCA dose (2 ml), and lockout interval (15 min) for groups MK and BK. We measured the interval to the first flatus during the 72 hours following surgery and recorded the numerical rating score (NRS) of pain with side effects at 1, 6, 12, 24 and 48 hrs postoperatively. RESULTS: Ketorolac expedited the return of bowel function significantly (P < 0.05). Analgesic efficacy and side effect were not significantly different in all three groups. CONCLUSIONS: IV PCA with meperidine-ketorolac and butorphanol-ketorolac afforded equal analgesia compared to the meperidine only. It also allowed earlier recovery of bowel function in patients undergoing gynecologic surgery.