Stool with bright red blood after chemotherapy for stomach cancer is abnormal. Chemotherapy for gastric cancer patients may lead to severe gastrointestinal reaction, often with violent vomiting, which may damage the mucous membrane of gastrointestinal tract and cause local damage and bleeding, resulting in blood in stool, and chemotherapy may lead to obvious bone marrow inhibition and lower platelet count, which may also cause gastrointestinal tract bleeding with the symptom of blood in stool. If gastric cancer patients have bright red blood in stool after chemotherapy, if the bleeding is large, they can use triple-lumen bursa tube to stop bleeding in time, and at the same time, follow the doctor’s instruction to take hemostatic drugs such as phenolsulfonyl ethylamine, tranexamic acid and so on. After chemotherapy, stomach cancer patients must actively observe whether there is any adverse reaction, and once fresh blood in stool is found, they need to consult doctor in time for proper treatment and treatment, so as to prevent delaying the condition and leading to serious consequences.