Doing a gastroenteroscopy without diarrhea has a relatively large impact if there is a lot of residual feces, but a small amount of residue has a relatively small impact. When doing gastroenteroscopy, if there is residual food or gastric fluid in the stomach and a large amount of feces and fecal fluid present in the intestines, there is a possibility that some subtle lesions in the stomach and intestines may not be observed properly, and there may be a missed diagnosis. However, when doing a gastroenteroscopy, if there is simply a small amount of residue on the stomach wall or intestinal wall, it will generally not affect the examination. Therefore, the exact impact of not having diarrhea when doing gastroenteroscopy is somewhat related to the amount of residue in the stomach and intestines. In order to improve the accuracy of the results of gastroenteroscopy, it is recommended to follow the doctor’s instructions and make the appropriate preparations before the examination.