Why is my stool black?

Normally, the feces excreted should be yellow or dark yellow, which is a normal bowel movement. However, some people find that the feces are black or even dark red. In this case, many people think it is blood in the stool. In fact, it does not only include blood in the stool. It may also be related to the blood of animals eaten, invisible bleeding in the stool, and inflammatory diseases in the intestines. All of these may cause the stool to appear black, which is mainly related to indigestion.

If you eat animal blood, liver and more meat, or take iron or carbon supplements, your stool may be black. In the former case, the stool occult blood test may be positive.

Common causes of black stools include:

1. Digestive tract diseases: The most common cause of bloody stools, including esophageal varices, esophageal foreign bodies, ulcer disease, acute gastritis, gastric mucosal prolapse, intussusception, hemorrhagic necrotizing enteritis, strangulated intestinal obstruction, Meckel's diverticulum, intestinal polyps, anal fissures, etc.

2. Blood diseases: neonatal hemorrhagic disease, hemophilia, leukemia, aplastic anemia, thrombocytopenia and allergic purpura, etc.

3. Other systemic infectious diseases, such as sepsis, typhoid fever, etc., newborns swallowing blood from the mother's birth canal or ruptured nipples, swallowing of bleeding from the nose, pharynx, and gums, etc.

4. Influence of food or medicine: Certain foods and medicines can also cause changes in stool color, which can sometimes be easily confused with blood in the stool. For example, eating a lot of watermelon and tomatoes in the summer can make the stool turn red. The stool of children with anemia can turn black after taking iron supplements. The stool can also turn black after eating animal blood. These changes in stool color caused by food and medicine do not constitute bloody stools.