A day or two before the gastroenteroscopy, patients should start preparing. Here are some precautions to take before the gastroenteroscopy: You should not smoke two days before the gastroscopy, because smoking will cause the secretion of stomach acid, which will affect the throat and lead to a sensitive throat during the examination, making the examination more painful. Do not eat eight hours before the gastroscopy, and do not drink water for four hours before the examination. Also, relax and don’t be too nervous before the gastroscopy. Learn about the gastroscopy process in advance so that you can cooperate well with the doctor during the examination. It is also important to make an appointment in advance, especially in large hospitals where there are more patients doing the examination and the appointment time is long, you should make an appointment in advance. Be sure to consult clearly about your examination time. If you are an elderly person, it is best to have the company of a loved one so that the patient is not too nervous, and if you have dentures or jewelry, remove them all before the examination. It is also best to urinate promptly if you have the urge to urinate before the examination, and not to hold it in. Patients with a history of heart or respiratory disease should inform the doctor in time that an electrocardiogram or respiratory examination may be required before the examination, and if necessary, they should also be treated in advance so that accidents will not be found during the examination. The above are the precautions to be taken before the gastroenteroscopy. With careful preparation, the examination will generally be relatively smooth.