Causes of blood pulling include upper gastrointestinal tract diseases, lower gastrointestinal tract diseases, systemic diseases and so on. 1. Upper gastrointestinal diseases: mainly include peptic ulcer, gastric cancer, esophageal cancer, biliary roundworm, bile duct cancer, gallbladder cancer and so on. 2. Lower gastrointestinal diseases: mainly including acute hemorrhagic necrotizing enteritis, acute bacillary dysentery, schistosomiasis, rectal polyps, rectal cancer, hemorrhoids, anal fistula, anal fissure, etc. 3. Systemic diseases: mainly including hemophilia, leukemia, uremia, sepsis, thrombocytopenic purpura and so on. Blood pulling is a more serious symptom, it is recommended that patients should seek timely medical treatment, improve the relevant examinations, such as routine blood tests, routine stool examination, gastroenteroscopy, etc., to avoid neglecting the condition, so as not to delay the treatment of the disease.