Black stool? What's going on?

Stool blackening must be alert to two situations: one is that the patient shows black stool, which is a manifestation of gastrointestinal bleeding, and another situation is caused by interference from some other factors. Generally, it is necessary to check the routine, if the stool occult blood is positive, then it can be concluded that it is gastrointestinal bleeding, especially the possibility of gastrointestinal bleeding is higher; if the stool occult blood is negative, it is ruled out that the possibility of gastrointestinal bleeding is possible, and there are several other possible causes of stool color blackening: The first is oral gastric mucosa protective agent, this bismuth agent can cause black stool; the second oral animal blood products, such as duck blood; there is a possibility that eat more vegetables, stool color is darker, in fact, the color is not black.