We studied the time to postoperative micturition and the duration of analgesia in 82 children aged 6 mo to 10 yr undergoing herniorrhaphy or orchiopexy under general anesthesia with N2O and halothane. All received D5 lactate Ringer's solution equivalent to 6 h maintenance intraoperatively, and oral fluids postoperatively ad libitum. At the end of surgery, patients were randomly assigned to receive one of three regional anesthetic injections using 0.25% bupivacaine: caudal, 0.75 mL/kg (group I); caudal with 1:200,000 epinephrine, 0.75 mL/kg (group II); or ilioinguinaliliohypogastric nerve block with epinephrine through the wound by the surgeon (group III). Postoperatively, blinded observers scored pain at 30 min, hourly until discharge, and by telephone at 24-36 h. In the 74 patients with successful blocks (mean age 2.5 +/- 2.4 yr), the times to micturition (group I, 202 +/- 130 min; group II, 262 +/- 164 min; group III, 196 +/- 101 min) did not differ significantly among groups. Seven patients who took more than 8 h to void required no intervention. There was no difference in the numbers without pain for > or = 4 h (74%, 64%, and 69% of groups I, II, and III), or those requiring analgesics by 24 h (66% overall). The time to postoperative voiding in children is variable and not prolonged by caudal analgesia; caudal bupivacaine with or without epinephrine and ilioinguinaliliohypogastric nerve block are equally effective for postoperative analgesia.