Taking quadruple therapy for stomach upset is usually caused by the side effects of antibiotics, but may also be a symptom of gastrointestinal disease itself. 1. Drug side effects: quadruple therapy includes proton pump inhibitors, gastric mucosal protectants and several antibiotics, such as penicillin, metronidazole, clarithromycin and so on. If you use antibiotics, it will cause some stimulation to the gastric mucosa, which will lead to stomach discomfort. This is the time to stop the medication and seek medical attention. Although side effects such as allergy to proton pump inhibitors or gastrointestinal mucosal protectants occur less frequently, they cannot be completely excluded. 2. Gastrointestinal diseases: Gastritis, peptic ulcer and other diseases caused by Helicobacter pylori infection may lead to discomfort such as burning sensation in the stomach. When the symptoms worsen, we should consult the doctor in time to clarify the cause of the disease. In the process of taking medication, we should pay attention to avoid smoking, alcohol, spicy, greasy, cold and other foods, try not to stay up all night, to have enough sleep, otherwise it will lead to deterioration of the condition, resulting in poor therapeutic effect.