Black is upper gastrointestinal bleeding?

Black stool is not necessarily caused by upper gastrointestinal bleeding.

Black stool usually refers to the color of stool being black or dark red, similar to the appearance of coffee grounds, and this phenomenon is often related to upper gastrointestinal bleeding. Because the stomach, esophagus or duodenum After bleeding occurs in the upper digestive tract such as duodenum, hemoglobin in the blood oxidizes under the action of gastric acid to form black iron sulfide, resulting in black stool. However, in addition to upper gastrointestinal bleeding, eating animal blood products, taking iron and other factors, the above symptoms may also occur, not necessarily caused by upper gastrointestinal bleeding.