There are many bismuth-based gastric drugs, of which the most commonly used are the following: aluminum phosphate gel, bismuth aluminate granules, bismuth pectin, bismuth potassium citrate. Among them, aluminum phosphate gel is a paste preparation, bismuth aluminate granules is a granule, the two drugs before meals a small amount of water, can be evenly attached to the esophagus and gastric mucosa surface, inhibit gastric acid and anti-Helicobacter pylori, better efficacy. In addition, patients taking bismuth-based gastric drugs often have black stools, which need to be distinguished from black stools caused by gastrointestinal bleeding. Patients can be differentiated by fecal occult blood test, which is negative for black stool caused by bismuth drugs and positive for black stool caused by gastrointestinal bleeding, so it is not difficult to differentiate.