Stomach cancer will vomit in the late stage. Once the tumor grows to an advanced stage, it will cause obstruction to the lower output tract, i.e. most gastric cancer patients cannot eat, vomit immediately after eating, or vomit overnight food in the early morning, so you should pay attention to the obstruction caused by gastric cancer that may lead to vomiting. However, the vomiting caused by gastric cancer is different from the usual vomiting, there is rarely green bile-like stuff, so when vomiting occurs, we should carefully observe whether there is blood or bile in the vomit and ask the medical history to clarify whether there is pyloric obstruction.