Quadruple combination refers to four medications for the eradication of H. pylori, which contain two antibiotics, a proton pump inhibitor, and a bismuth agent. The order of taking them is mainly taking proton pump inhibitor and bismuth before meal, and taking antibiotics after meal, mainly as follows: 1. Proton pump inhibitors: take proton pump inhibitors half an hour before meals, commonly used drugs are omeprazole, rabeprazole, pantoprazole, esomeprazole and so on; 2. bismuth: take about half an hour before meal, including colloidal bismuth pectin, compound bismuth aluminate, bismuth potassium citrate; 3. Antibiotics: take antibiotics immediately after meals. Commonly used antibiotics include amoxicillin, clarithromycin, metronidazole and furazolidone. There is no special order required for the two antibiotics taken after meals. When using quadruple drugs to treat Helicobacter pylori, avoid overeating and drinking, do not stop or change drugs without authorization to avoid side effects, and avoid drinking alcohol when applying antibiotic treatment such as furazolidone. The course of treatment is 10-14 days, and the therapeutic effect can be reviewed 1 month after stopping the drug. If the patient has a history of allergy to penicillin, it should be explained in time before the doctor prescribes the medicine.