Digestive tract bleeding, black stool?

Black stool refers to black stool. Patients with gastrointestinal bleeding generally pull black stool.

Gastrointestinal bleeding refers to the phenomenon of local bleeding in the digestive tract, which can include esophagus, stomach, duodenum, small intestine, etc. When bleeding occurs, the divalent iron ion in hemoglobin is easily converted into trivalent iron ion after digestion, such as pancreatic juice, gastric acid, intestinal

juice, etc.