Generally speaking, whether stomach pills are to be taken before or after meals is related to the method of use of the specific drug, and there is no uniform method of use for all stomach pills. The method of eating can be roughly divided into meal and after meal, etc.. 1. Eat before meals: the method of taking gastric drugs are mostly used for the protection of the gastric mucosa, can form a layer of protective film, to avoid the gastric acid secretion after eating the gastric mucosal stimulation, such as aluminum sulfate. Aluminum thioglycollate is mostly used for gastric and duodenal ulcers, renal insufficiency is prohibited, there may be constipation and other adverse reactions, need to pay attention to the long-term use of the drug to monitor the accumulation of aluminum. 2. Eat after meals: This method of taking gastric drugs is used in the case of excessive secretion of gastric acid after eating, such as cimetidine. Cimetidine is mostly used for gastric and duodenal ulcers, and is contraindicated in people who are allergic to cimetidine, which may cause adverse reactions such as diarrhea and nausea, and care should be taken not to stop the drug suddenly. The above drugs are recommended to use the above drugs under the guidance of a doctor, avoid self-medication.