Blood in the stool

Blood in the stool (hematochezia): Blood comes out of the anus, bleeding with or without stool. It is generally believed that the amount of gastrointestinal bleeding above 50 ml is likely to cause black stools. Because iron in hemoglobin combines with sulfide in the intestine to form iron sulfide, the stool is black like tar. Hematemesis usually has melena. Blood is excreted from the anus, the stool is bloody, or all bloody stools are bright red, dark red, or tar-like, which are all called blood in the stool. Blood in the stool is generally seen in lower gastrointestinal bleeding, especially in the colon and rectum, but occasionally upper bleeding is seen. The color of blood in the stool depends on where the digestive tract is bleeding, the amount of bleeding, and how long the blood stays in the intestine. Blood in the stool with bleeding from the skin, feline membrane, or other organs is more common in hematological diseases and other systemic diseases. Such as leukemia, disseminated intravascular coagulation and so on. There are many causes of blood in the stool. Almost all gastrointestinal bleeding can cause blood in the stool, but the common reasons are: ① upper gastrointestinal bleeding (see Hematemesis). ② Small intestinal bleeding, such as intestinal tuberculosis, localized enteritis, acute hemorrhagic necrotizing enteritis, small intestinal tumors, intussusception and so on. ③ Colonic bleeding, such as dysentery, ulcerative colitis, localized enteritis, colon cancer, etc. ④ rectal bleeding, such as rectal cancer, rectal damage, hemorrhoids, anal fissures, etc. ⑤ Other diseases, such as various blood diseases, epidemic hemorrhagic fever, typhoid and paratyphoid fever, hookworm disease, vitamin deficiency, etc. Upper gastrointestinal bleeding and small intestinal bleeding are mostly dark red or black stools. Because the surface is covered with a thin layer of mucus, it is often shiny. However, if the bleeding speed is fast, the amount of bleeding is large, and the intestinal motility increases, the blood can be dark red or bright red. Colon and rectal bleeding, because the blood stays in the intestine for a short time, often bright red or bright red bloody stools. The right colon is bleeding, and the blood is often mixed with feces, which can drain "jam-like" blood. Rectal and sigmoid bleeding, blood is often attached to the surface of feces. Acute large amount of blood in the stool, patients may appear acute hemorrhagic anemia and acute peripheral circulatory insufficiency. The diagnosis of blood in the stool is based on medical history and physical examination data, and digestive endoscopy is the first choice. If necessary, X-ray barium, radionuclide, angiography and other tests can also be performed to help diagnosis.

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