Gastroscopy can not drink water, because drinking water will affect the gastric mucosa, affecting the accuracy of the gastroscopy results. Before the gastroscopy, you should also pay attention to: 1. do a full body check, because some people such as cardiovascular disease or pregnant women are not suitable for gastroscopy, so you need to do electrocardiogram, blood tests, etc., before you decide to do the gastroscopy time. 2. do a good job of cleaning the stomach, eight hours before the gastroscopy to prohibit food and water, to ensure that the stomach is empty when doing the gastroscopy. 3, adjust the mentality, do the general gastroscopy process will be a little discomfort, but will not bring great impact on the body, so you need to relax, but also pay attention to wear some loose clothing on the day of the examination.