Drinking water before gastroscopy should be based on the amount of water consumed to determine whether it has any effect on the examination. A small amount of water usually has no effect, and it is recommended that the examination be postponed if the amount of water consumed is too high. If you are having an ordinary gastroscopy, drinking a small amount of water before the examination will not affect the examination process and no special treatment is needed. Because the water is clear and transparent, it basically will not cause obstruction to the image observation. If you drink too much water, you can delay the gastroscopy appropriately and wait until the liquid in the stomach is emptied before performing the gastroscopy to avoid choking and suffocation. If painless gastroscopy is performed, it is recommended to cancel it for the time being, because this examination requires intravenous anesthesia for the patient, and the patient is in an unconscious state during the examination, and if the patient drinks water before the examination, choking and coughing and other accidents may occur during the examination. If there is any abnormality, please actively seek medical treatment, ask professional doctors to judge their own condition, and carry out adequate treatment to promote health.