 Opioids are widely used for pain relief after major abdominal surgeries1. Sex differences in the opioid analgesia have been reported and investigated in human subjects and animal models In this study, effects of sex difference on response to opioid analgesics after abdominal surgeries will be assessed regarding; analgesic duration primary variable, frequency of analgesic requirement, total opioid consumption, Opioid related complications respiratory depression, Nausea vomiting, itching, over-sedation, delayed intestinal motility. 