this prospective randomized double blind controlled study was conducted on 60 child scheduled for lower abdominal surgery under general anesthesia. the patients were randomly allocated into 3 parallel groups.group (ESB) patients received ultrasound-guided erector spinae block in a dose of 0.4mg/ml of 0.25%bupivacaine between the 10th transverse process and erector spinae muscles.group(CB) patients received ultrasound-guided caudal block in a dose of 2.5mg/kg of 0.25%bupivacaine. group(CO) did,t received any block

on arrival of the patients to the operative theatre and after placement of the standard monitoring general inhalational anesthesia was induced by face mask with sevoflurane (4-8%) in oxygen after IV cannula was secured patients received 1mic/kg fentanyl and intubation was facilitated by 0.5mg/kg atracurium. isoflurane 1-2% with oxygen was used for maintenance of anesthesia. after stabilization of the patient's hemodynamics and before skin incision erector spinae block or caudal block was performed with the patient in lateral position. after the block patients were flipped back to their normal supine position, surgery took place 10 min after injection of local anesthetic. after termination of surgery reversal of the atracurium was done by giving neostigmine in a dose of 0.04mg/kg and atropine 0.02mg/kg and awake extubation was done

Inclusion Criteria:

• pediatric patients aged 2-6 years scheduled for lower abdominal surgery under general anesthesia

Exclusion Criteria:

• parent refusal
• spinal and meningeal anomalies
• mental retardation
• blood disease
• infection at site of injection
• drug allergy