There is no such thing as whether it is better to do gastroenteroscopy in the morning or in the afternoon, but it is usually relatively convenient to do it in the morning because gastroenteroscopy requires fasting. You can’t eat for gastroenteroscopy, you need to fast for more than 8 hours, so it’s relatively convenient to do gastroenteroscopy in the morning. However, from the point of view of the examination results, the choice of what time to do does not have an impact. In addition to fasting, you should clean up your intestines for gastroscopy, that is, you should empty all the feces in your intestines before the examination, and you can take some medicines before the examination so as to clean up your intestines, for example, magnesium sulfate, compound polyethylene glycol electrolyte dispersant. If it is necessary to have a gastroenteroscopy and you need to go to the hospital for an appointment to clean out your intestines first, you should also choose the medication under the guidance of your doctor and have the examination according to the appointment time.