Carbon 13 negative means that there is no H. pylori infection, whereas positive means that an infection is present and requires antimicrobial treatment with triple or quadruple drugs. Carbon 13 refers to the carbon 13 breath test, which can be used to detect H. pylori infection, and there is now a carbon 14 breath test of the same type. The normal range for the carbon 13 breath test is 0 to 4. A test within this range is considered negative and indicates that the subject is not infected with H. pylori. If the test value is 4 or more, it suggests that the patient is infected with H. pylori, and can be given proton pump inhibitors (such as omeprazole), bismuth (such as colloidal bismuth pectin) and two kinds of antibiotics (such as amoxicillin and furazolidone), the course of treatment is usually 10 to 14 days, and those who can tolerate it should use it for 14 days as much as possible, and the effect of the treatment should be rechecked after the completion of the treatment after stopping using the medication for 1 month. Specific medication should be under the guidance of a specialist, not unauthorized use of medication.