Black Stool
If your poop is black (i.e., a deep coffee black color), it signifies gastrointestinal bleeding in upper areas like the stomach. Because the poop will take a while to travel down the body, the blood will become older and darker. It can be because of black licorice, black stout, iron supplements, or bismuth pills in the body.
Also, some medical conditions, such as esophageal varices, gastric ulcers [4], and gastritis, tend to cause stool to look almost black or tar-like. However, it is essential to visit your healthcare provider quickly when noticing black stools, as black stools are not caused by foods and other supplements.