CLEAR FLIUIDS. See npo answer. You shoudl drink clear fluids npo is 20 years out of date and worse for many reasons.
Nothing. If you are undergoing general anesthesia, you may not eat or drink anything for at least eight hours prior to your procedure. This includes water. The reason for this is that the anesthesiologist wants to keep your stomach empty to prevent contents from getting into your airway during the induction of anesthesia.
Nothing. It is best to eat or drink nothing in the period before anesthesia. Commonly this is nothing to eat or drink after midnight.
See below. The anesthesiologist will ask you to eat nothing for at least 6 hours before the operation. They may allow you to have some clear liquids (water, apple juice, coke) up until two hours before surgery. Always check with your anesthesiologist for their preference. I suggest to my patients that they have light meals with plenty of liquids the day before surgery. Good luck with your operation.