Metronidazole has a certain degree of irritation to the stomach, which is mainly manifested as stomach discomfort, loss of appetite, nausea or in severe cases, vomiting, so it is recommended to take it after meals and not to drink alcohol for three days, and 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 mucosa protector, acid suppressant and other drugs for treatment. Patients should pay attention to the regularity of diet, eat on time, eat less and more meals, mainly light, do not eat raw, cold, greasy and stimulating food.