Poop is generally brown, but, at times, it can turn green, red, black, yellow ... Stool is usually light to dark brown. A substance from red blood cells called bilirubin ends up in the intestines.

It usually transitions to greenish-yellow poop by three or four days. Babies who drink iron-enriched formula may have very dark green or black diarrhea. This is a benign reaction to the added iron ...

Meconium – your baby's first poop – is very dark green, looking almost black. It's made up of amniotic fluid, skin cells, ...

This is a common and expected side effect of the iron. Taking iron can also make your poop appear dark green or nearly black. Vitamins are considered water- or fat-soluble based on how your body ...