Gastroscopy requires an empty stomach and is usually best performed in the morning. Fasting is necessary for gastroscopy because the presence of food residue in the stomach may interfere with the observation of the stomach structure, leading to partial leakage of stomach lesions. Therefore, it is generally necessary to maintain a fasting period of at least 6 hours for gastroscopy. Therefore, gastroscopy generally requires that no food be consumed after 8:00 p.m. on the night before the examination, and that water fasting be continued before the examination on the second day. Gastroscopy is usually best done in the morning time, due to the fact that food can not be eaten until after the gastroscopy is completed, so it can be done in the morning as soon as possible to allow the examined person to eat, to avoid fasting for too long to cause dizziness, weakness and other uncomfortable manifestations. Therefore, it is recommended to maintain strict fasting and fasting before gastroscopy, and consult a medical professional for standardized treatment if necessary.