A liquid diet is recommended the day before the gastroenteroscopy, avoiding foods rich in crude fiber and fasting 8 hours before the examination. For people who need to do gastroenteroscopy, it is recommended to confirm the time of examination, and the day before the examination, it is recommended to have a liquid or semi-liquid diet, which can be consumed as rice porridge, millet porridge, thread noodles, etc. Avoid foods rich in crude fiber, such as vegetables, fruits and beans, etc., so as to avoid food residues from affecting the examination field of view and interfering with the results of the examination. It is recommended that people who are physically fit to be examined should fast for 8 hours before the examination and prepare the bowel in about 4 hours, i.e., take laxative drugs prescribed by professional doctors, such as polyethylene glycol, mannitol, etc. Taking laxative drugs will lead to multiple bowel movements and even watery stools, which is a normal phenomenon, and emptying of the bowel can increase the accuracy of the gastroenteroscopy examination. Before doing gastroenteroscopy, it is recommended to eat easy to digest food, the day before it is recommended to eat liquid or semi-liquid diet, eat less crude fiber food, follow the doctor’s instructions for intestinal preparation, so as not to interfere with the results of gastroenteroscopy.