What happens when shit is black?

Black stool may be caused by diet, taking drugs, gastrointestinal bleeding, etc.

If the patient recently eats too much iron-containing food, such as pig blood, duck blood, pig liver, etc., or takes iron, such as ferrous sulfate tablets, ferrous succinate tablets, ferrous fumarate tablets, etc., it will cause stool to appear black. If the patient suffers from gastric ulcer, gastritis, duodenal diverticulum, ulcerative colitis, bacterial dysentery and other diseases, it will cause gastrointestinal bleeding. Blood is digested and decomposed in the stomach or intestinal tract. After oxidation, it will be discharged with stool, which will make stool black.