There is no significant difference between painless gastroenteroscopies done together and separately, and there is no such thing as whether they are done well separately or together.
Gastroscopy screens for stomach and duodenal disease, and colonoscopy screens for colorectal disease; these are two parts of the body that can be done separately or together.
If a patient wants to check the stomach and duodenum and also screen the colon, they can choose to have them done at the same time, under intravenous anesthesia, with no pain to the patient.
Some preparation is needed before painless gastroenteroscopy is done at the same time. Fasting and bowel cleansing are required before the examination, and a family member is also required to accompany the patient because general anesthesia requires signing an anesthesia consent form.
The examination should be carried out under the guidance of a physician.