Why should we fast water before and after the operation?

No water and no food after non-digestive tract surgery-the patient has no ability to eat (such as coma, oral intubation, etc.). ) and prevent reflux aspiration (choking reflex is suppressed when anesthesia is not awake, water and food easily enter the lungs, causing aspiration pneumonia, which is the case in most patients).

Don't eat or drink water after digestive tract surgery-it will take some time for the anastomotic stoma to grow well after surgery (if you don't eat well, the food may leak into the sterile environment such as chest and abdomen, and the food is bacterial and the gastric juice is irritating, which will be very troublesome), and it will take some time for the intestinal function to recover (if you don't recover after eating, it may cause paralytic intestinal obstruction).

Very few people can't get nutrition after eating because of the abnormal anatomical structure after total small bowel resection, so it's useless to eat and need total intravenous nutrition. But after the wound heals, you don't have to completely fast, just eat less, but after eating it, you are just addicted to your mouth and the food can't be absorbed.