There is no harm if gastroenteroscopy is done together, but it mainly depends on whether the patient himself can tolerate it or not, and the patient may experience symptoms such as abdominal distension, abdominal pain, nausea and vomiting. Both gastroscopy and colonoscopy involve injecting gas into the digestive tract. If too much gas is injected, patients may experience significant abdominal bloating and pain, and both transoral gastroscopy and anal colonoscopy will bring discomfort to the body to a certain extent, potentially leading to symptoms such as nausea, vomiting, and anal pain. Although the harm is not great, many patients are not able to tolerate it, so it is recommended that gastroenteroscopy be done separately. In addition, many hospitals now have anesthesia monitoring equipment in the gastroscopy room, if you want to do at the same time, you can choose the painless gastroenteroscopy, which can greatly reduce the discomfort of gastroenteroscopy. If you don’t want to do it at the same time, you should inform your doctor in advance and make another appointment for another examination.