Quadruple refers to quadruple therapy, usually there is no obvious adverse reactions after stopping most of the drugs, very few may cause abdominal distension, diarrhea and other symptoms, usually 2~3 days can disappear. 1. Quadruple therapy in accordance with the regular dose of standardized medication, usually no obvious adverse reactions after stopping the drug. However, because of the antibiotics in quadruple therapy, there may be a certain impact on the intestinal flora, a small number of people may experience mild abdominal pain, diarrhea symptoms, most of which can disappear in 2~3 days after stopping the drug. 2. If metronidazole is applied in quadruple therapy, it may cause side effects such as nausea and vomiting, loss of appetite, headache, etc., which may last for a period of time after stopping the drug, but most of them will disappear soon. If the discomfort cannot be relieved for a long time after stopping the medicine, it is recommended to consult a doctor in time to clarify the cause of the disease and follow the doctor’s instructions.