Carbon 13 breath test is harmless and can be done immediately after gastroscopy if there is no discomfort. Currently, the carbon 13 or carbon 14 breath test is the most widely used clinical test for detecting H. pylori infection. It is simple, non-invasive and widely used to assist in the clinical diagnosis of H. pylori infection. After gastroscopy, we should pay attention to observe the postoperative changes in the body, eat a light diet, and pay attention to rest. Carbon 13 breath test can be performed if there is no discomfort. There is no specific symptom of H. pylori infection, if you suspect that there is H. pylori infection or discomfort, it is recommended that you consult a doctor in a timely manner, under the guidance of the doctor, combined with the results of the relevant tests, to make a definitive diagnosis, so as to avoid delaying the condition.