The mouth to the duodenum is called the upper GI tract, and the part below the jejunum is called the lower GI tract, including the jejunum, ileum, colon, and rectum. In general, bleeding from upper GI tract lesions results in black or even tarry stools. In lower GI bleeding, the blood is often bright red or dark red in color. Blood in the stool has the following causes: 1, hemorrhoids, blood in the stool occurs in the process of defecation, or after the stool is dripping or spraying, blood is bright red, blood and stool do not mix; 2, anal fissure, anal fissure caused by blood in the stool, blood is bright red, dripping out or hand paper wipe after the blood, and after the stool there is severe anal pain; 3, rectal colon polyps, blood is bright red, no pain, blood and stool do not mix; 4, ulcerative colitis The bleeding mixed with mucus or pus-blood stool, accompanied by abdominal pain, or fever, frequent stools; 5, rectal cancer, caused by bleeding stools, manifested as mucus-pus-blood stool, or dark red blood stool; 6, bacterial dysentery, the amount of blood in the stool may be less, often mixed with stool in pus-blood or pus-blood mucus-like stool, bright red blood, increased stool, with a sense of urgency and left lower abdominal pressure pain, and accompanied by There are also symptoms of abdominal pain, diarrhea, nausea and vomiting. In small clinics, due to the lack of equipment and many causes of blood in stool, misdiagnosis and mistreatment often occur, especially for early internal hemorrhoids and early rectal cancer, both of which have blood in stool, and the misdiagnosis rate is high. According to statistics, more than 80% of rectal cancer patients have been misdiagnosed as internal hemorrhoids in the early stage, missing the best time for treatment, so accurate examination of blood in stool is of great significance. In life, if you find yourself suffering from some symptoms of anorectal diseases, you must go to a professional anorectal hospital for examination and treatment in time.