How long before the hemorrhoid surgery can not eat should be based on the specific anesthesia of the operation, local anesthesia before the operation can eat normally, if it is lumbar anesthesia or sacral anesthesia can not eat 6-8 hours before the operation, 3-4 hours before the operation can not eat water. 1. local anesthesia: hemorrhoid surgery is a surgical way to remove hemorrhoids, local anesthesia around the hemorrhoids, conducive to the operation of the surgery, for hemorrhoids is not too serious patients can choose local anesthesia, after anesthesia, the patient has a sense of autonomy, control of urination and defecation, will not have an impact on the operation, so before the operation can be normal eating. 2. Lumbar anesthesia, sacral anesthesia: If the hemorrhoids are large, bleeding, serious symptoms, usually lumbar anesthesia or sacral anesthesia for surgery, this anesthesia may lead to aspiration, respiratory difficulties, vomiting, pneumonia, etc., so it should be strictly required to fast for 6-8 hours before the operation, and not to drink water for 3-4 hours before the operation. Therefore, the preparation for hemorrhoid surgery should be strictly in accordance with the doctor’s recommendations and follow the doctor’s instructions, and should not be self-initiated, causing unnecessary results.