Gastric blow test refers to carbon 13 or carbon 14 test, which is used to check for Helicobacter pylori infection, and requires fasting and discontinuation of antibiotics, bismuth, proton pump inhibitors and other medications before the test. 1. Gastric blow test is used to determine H. pylori infection by exhaling and requires fasting to avoid affecting the accuracy. If you have already eaten on the same day, you need to wait for 4-6 hours before performing the test. 2. Gastric blow test has carbon 13 breath test and carbon 14 breath test, if you have taken antibiotics such as furazolidone, amoxicillin, bismuth such as bismuth potassium citrate, acid suppressant such as omeprazole and other medicines within one month, it may lead to false-negative results, so you need to stop taking medicines for one month before taking the test, and you can resume taking the medicines after completing the test. It is recommended that patients who need to undergo a gastric blow test go to a regular hospital, consult a doctor and complete the test under the doctor’s guidance.