It is best not to eat during the gastroscopy. Patients are advised to go to the hospital in the morning on an empty stomach to register for a consultation, and the department of gastroenterology is generally preferred. If the patient has symptoms of stomach discomfort, the doctor will usually give a gastroscopy application form and recommend the patient to have an electronic gastroscopy, so the patient must not eat, otherwise it will affect the gastroscopy. If there is vomiting or upper gastrointestinal bleeding, it is also not advisable to eat. If the patient goes for a normal follow-up, there is no need for gastroscopy and no need to draw blood from the vein, so the patient can eat normally. However, in general, it is advisable to have an empty stomach because it involves gastroscopy or phlebotomy.