What kind of surgery did you have? Usually after surgery this function should return in 48 to 72 hours. Yes, GA can slow the gut down as well as pain meds, etc.
Are you eating well yet? Drinking well yet?
sorry just read above i see it is constipation..
If you dont wan to try foods. go to your chemist and they will give you somting to help things along.. but if your taking about not urinnating then straight to see a doctor.