Patients with gastrointestinal bleeding can easily manifest as anemia, especially for patients with chronic blood loss. Patients will also have significant weakness, loss of appetite, weight loss, and frequent black stools. In daily life, while actively treating the primary disease, attention should be paid to supplementing the diet with animal protein and also with appropriate iron supplements, eating more dark vegetables, including spinach and eggplant, etc. If necessary, ferrous sulfate or iron sucrose injection can also be given intravenously. It is also important to routinely apply drugs to protect the mucosa of the gastrointestinal tract and stay away from bad habits, because some patients have anemia secondary to abnormal vitamin metabolism caused by years of drinking strong tea. In patients with recurrent gastrointestinal bleeding, symptomatic treatment such as blood transfusion is also required if necessary.