BACKGROUND: Epidural morphine is usually associated with decreased bowel motility and increased transit time. Low doses of intravenous naloxone have been known to reduce morphine-induced side effects including intestinal hypomotility without reversing analgesia, but the effect of epidural naloxone has not been defined in human study. Therefore we evaluated bowel motility and analgesia when naloxone was administered via epidural route. METHODS: Forty-two patients having epiduro-general analgesia for total hysterectomy were randomly assigned to one of two study groups. As a means of postoperative pain control, all received 1.5 mg of epidural morphine bolusly 1 hour before the end of surgery, and a continuous epidural infusion was started using a two-day infusor containing 2.5 mg of morphine in 0.125% bupivacaine 100 ml with either no naloxone (control group, n = 20) or 5 microgram/kg/day of naloxone (experimental group, n = 22). We measured the time to the postoperative first passage of flatus and feces to evaluate the restoration of bowel function, and visual analog scales (VAS) for pain during rest and movement. Scores were taken at 2 and 4 hours after the operation, 7 AM, 1 PM, and 7 PM of the 1st postoperative day and 7 AM and 1 PM of the 2nd postoperative day. RESULTS: The experimental group revealed less time to the first postoperative passage of flatus and feces. No significant difference was found in resting and movement VAS between the two groups. CONCLUSIONS: This study suggests that epidural naloxone reduces epidural morphine-induced intestinal hypomotility without reversing analgesic effects.