 The aim of this study is to compare the analgesic efficacy of ultrasound guided posterior quadratus lumborum block and subcostal transversus abdominis plane block in laparoscopic cholecystectomy. The primary outcome will be assessment of postoperative opioid analgesic requirements. The secondary outcomes will include assessing intraoperative analgesic requirements, stress of trocar insertion and insufflation, postoperative visual analogue scale VAS, length of stay at post-anesthesia care unit PACU, time of first request to analgesia, incidence of nausea, and vomiting. 