Before the surgery, anesthesiologists at least the day before to see the next day’s surgery patients, especially small children’s parents will ask the child has the habit of eating in the middle of the night, or in the morning is very hungry can you eat, or can you eat a little bit less food, anesthesiologists can be very clear to tell you that this is not allowed at all, more, less are not allowed. Because without anesthesia, human beings have normal coughing and swallowing functions, but under anesthesia, these functions will be weakened or even lost. Anesthesia intubation or the surgical operation itself may also induce gastric reflux or vomiting. Once the food or water in the stomach is choked into the bronchial tube, it may cause aspiration pneumonia in mild cases, and in serious cases, it may cause airway obstruction and asphyxiation, which may directly jeopardize the safety of the patient’s life. Therefore, it is necessary to strictly follow the doctor’s instructions, that is, to strictly prohibit food and water. If necessary, the doctor will give fluids intravenously to make up for the lack of energy or water caused by fasting.