Many patients and their families do not understand that they cannot eat or drink before surgery, and some even believe that they need to eat well before surgery to better “tolerate surgery”. As a result, sometimes patients or family members do not listen to the physician’s advice or forget the nurse’s instructions and eat before the operation, and have to stop the operation and do it at another time. Gastrointestinal preparation is an important part of preoperative preparation, which is mainly to prevent asphyxia or aspiration pneumonia due to vomiting reaction during anesthesia or surgery. This vomiting reaction may occur at any time during anesthesia, especially during tracheal intubation, suction tube aspiration and catheter removal, and if anesthesia surgery is performed after eating and drinking, the stomach contents are not yet digested into the intestine under stimulation that vomits back out, which will not only affect the normal operation, but also may cause serious complications and even threaten the patient’s life.