The carbon 14 breath test is performed to detect the presence of H. pylori infection in the stomach. If the carbon 14 breath test is positive, it is indicative of H. pylori infection and is a current infection. Patients are advised to eradicate H. pylori, and a quadruple therapy is recommended, which consists of four oral medications, two antibiotics and an acid-suppressive drug, plus a bismuth agent. The choice of two antibiotics is currently recommended amoxicillin 1.0g twice a day and furazolidone 0.1g twice a day; bismuth is colloidal bismuth 0.2g twice a day; acid-suppressing drugs can be chosen from rabeprazole and esomeprazole, which are discontinued after 14 days of oral administration and reviewed again after one month of discontinuation.