You can’t drink water for gastroscopy because drinking water will cause the color of the gastric mucosa to change, which will affect the accuracy of the test results. Do gastroscopy before also pay attention to the following matters: 1, do gastroscopy before 6 hours can not eat any food and drugs, the night before you can eat a little easy to digest food, but can not eat too much. 2, do gastroscopy before to follow the doctor’s instructions, oral can clean up the stomach of the drug, the purpose is to reduce the mucus in the stomach, so that the image is more clear, and sometimes need to be injected to make the stomach become relaxation of the drug, so that the stomach peristalsis slows, need to actively cooperate with the doctor. 3, also remove the eyes, the collar and belt loosened, so that the results of the examination will affect the accuracy of the gastric mucosa. Need to actively cooperate with the doctor. 3, before the examination, but also to remove the eyes, the collar and belt loosening, easy for the doctor to check, if there is a movable dentures should also be removed, to avoid doing gastroscopy dentures into the respiratory tract, resulting in asphyxiation. 4, can not rinse your mouth immediately after the gastroscopy, can not eat any food within 2 hours, and then you can eat a little bit of appropriate liquid food.