Pulling blood is clinically known as blood in stool, which may be caused by hemorrhoids, anal fissure, gastrointestinal bleeding, tumor and many other reasons. 1. Hemorrhoids: If the patient himself has hemorrhoids, especially internal hemorrhoids, when the stool is too dry it is likely to cause hemorrhoids to bleed and blood in stool. 2. Anal fissure: trauma or too dry stool may cause anal tearing, called anal fissure, when anal fissure is also easy to cause blood in the stool, or wipe the paper with blood. 3. Gastrointestinal bleeding: Upper gastrointestinal ulcer, esophagogastric varices, ulcerative colitis and other diseases can lead to blood in the stool. Most of them are tarry stools or dark brown or dark red blood stools. 4. Tumor of digestive tract: If you suffer from tumor of digestive tract, when the tumor ruptures or damages the surface mucous membrane in the body, bleeding will occur, and when the bleeding is large, blood in stool may occur. There are many other causes of blood in stool, such as gastrointestinal polyps, intestinal parasitic diseases (hookworm disease, etc.), coagulation disorders (such as hemophilia, allergic purpura, etc.), and trauma. It is recommended that patients with blood in the stool should go to the hospital in time to complete the examination and identify the cause of the disease and then carry out targeted treatment.