Metronidazole has a certain degree of irritation to the stomach, it is mainly manifested as stomach discomfort, loss of appetite, nausea or vomiting in severe cases after taking it, so it is recommended to take it after meals and not to drink alcohol within three days, if patients have similar adverse reactions after taking it, they should stop the drug in time. If the adverse reaction is very serious, you can use appropriate gastric mucosal protective agent, acid suppressant and other drugs for treatment, patients can switch to omeprazole or other antibiotic treatment. If patients suffer from duodenal ulcer, gastritis, gastric ulcer and other gastrointestinal diseases, they can take penicillin drugs such as amoxicillin or clarithromycin and other antibiotics for treatment, and they can also take drugs to protect the gastric mucosa such as bismuth pectin. Patients should pay attention to the regularity of the diet, eat on time, eat less and more meals, mainly light, and do not eat raw, cold, greasy and stimulating food.