How long can you eat after anesthesia depends on the situation, specifically: 1, local anesthesia: you can eat from liquid after surgery; 2, intralesional anesthesia and nerve block: you can drink water 2 hours after surgery, you can eat liquid diet after 4 hours; 3, general anesthesia non-gastrointestinal surgery: you can eat 6 hours after surgery, after the patient is fully awake, no nausea, vomiting can also eat, but first give a liquid diet, and later change to semi-liquid or general diet; 4, general anesthesia gastrointestinal surgery: to be exhausted after eating from the liquid. If the patient is critically ill and undergoing gastrointestinal surgery, he should fast and drink after surgery and undergo parenteral nutrition or enteral nutrition.