Blood in the stool is usually seen in the lower gastrointestinal tract, especially in the colon and rectum, but occasionally in the upper gastrointestinal tract. The color of blood in the stool depends on the location of the bleeding, the amount of bleeding, and how long the blood stays in the intestine. What is bleeding in the stool? According to the characteristics of bleeding, it can be divided into: a. Fresh blood stool Mostly immediate bleeding, blood flows out of the blood vessels for a short time and is discharged through the anus with the stool, or directly after the stool. The appearance of the blood is similar to traumatic bleeding, bright red or purplish red, dark red, and can coagulate into a blood clot after a little time. Blood is often found in the following diseases: 1. Hemorrhoids: the most common disease in the anorectal clinic, all stages of internal and mixed hemorrhoids can cause bleeding in the stool, usually with fresh blood in the stool or dripping blood after the stool. External hemorrhoids generally do not bleed in the stool. The typical symptom of rectal low polyps is painless fecal bleeding. Bleeding during defecation, stop after the end of defecation, the amount varies, generally blood does not mix with feces, or polyp location is high, the number of polyps can also be mixed with feces. 3, rectal prolapse: anorectal clinic is generally visible, typical symptoms have early red swelling prolapse outside the anus, after a long time disease can have bleeding during defecation. 4, anal fissure: manifested as anal pain during defecation, which lasts for a period of time after defecation. Also accompanied by blood in the stool, bleeding in the form of blood attached to the surface of the stool, not mixed with the stool, some patients drip blood after the stool. To determine whether the above disease is the cause of blood in the stool, the diagnosis can be confirmed by examination with electronic anoscopy. Second, pus and blood stool (mostly a symptom of serious diseases, immediate treatment is recommended) That is, the excreted stool contains both pus and blood, and the blood is thinner in appearance and sometimes contains a lot of mucus. Pus and blood stool or blood containing mucus, often seen in the rectum or colon tumors and inflammation, possibly rectal cancer, colon cancer, ulcerative colitis, the need for immediate examination and treatment at the hospital. Third, black stool (tar-like stool) refers to black or brownish-black stool, also known as tar stool, is one of the most common symptoms of upper gastrointestinal bleeding. The main manifestation of upper gastrointestinal bleeding is black stool, often accompanied by other symptoms and signs such as vomiting blood, palpitations, weakness and anemia. Generally speaking, if the bleeding volume is small and slow, and the blood stays in the intestine for a long time, the discharged stool is black due to the action of intestinal fluid; if the bleeding volume is large and stays in the intestine for a short time, the discharged blood is dark red; the bleeding volume is particularly large and can be bright red when it is discharged quickly.