1. Preoperative fasting is to avoid anesthesia accidents. For example, reflux or vomiting of stomach contents can easily be inhaled into respiratory tract under anesthesia, leading to aspiration pneumonia and even suffocation and death.

2. It is not infusion after operation, but infusion during the whole operation. First of all, infusion opens the venous access for intravenous administration during anesthesia and surgery; Secondly, fasting before operation will lead to insufficient fluid volume (dehydration), and the influence of anesthesia will easily lead to insufficient blood volume during anesthesia, leading to hypotension. Therefore, it is necessary to change the liquid during the operation.

With regard to postoperative infusion, it is generally required to keep the infusion and return to the ward after operation. The infusion after the ward is based on the operation situation, and the general surgeon will use antibiotics and other drugs at this time.

-

Supplement: Your question will make the doctor dizzy. You said you should absolutely abstain from water before the operation. Why did you drink it? I just don't want to eat anything. I persisted all night. Why did you put it in this morning?

It takes at least 4 hours for your stomach to empty completely just by drinking water. It will take more than four hours to get up in the morning, and the operation will be difficult to arrange.