The most common causes of blood clots in the stool are as follows: 1, rectal lesions, including hemorrhoids, anal fissures and other anorectal lesions leading to gastrointestinal bleeding; 2, gastrointestinal diseases, such as inflammatory diseases, ulcerative colitis, bacterial dysentery, intestinal tuberculosis, rectal cancer, etc., which require colonoscopy to distinguish different causes and give different treatment and treatment; 3, systemic diseases, such as hematologic diseases, which are common in clinical practice Allergic purpura patients with intestinal mucosal bleeding or blood clots, hemophilia, leukemia, thrombocytopenic purpura and other hematological system diseases will also appear blood in the stool; 4, elderly patients taking herbal medicines to activate blood circulation and remove blood stasis, or oral aspirin, Poliovirus-type anti-platelet drugs, can also lead to intestinal bleeding situation, need to carefully ask the medical history to exclude.