We spend a lot of time thinking about abnormal poop. What does it mean when your poop is green? What about when your poop looks like a cracked sausage? Can poop spontaneously combust? (Yes.) Can it come out of your mouth? (Yes.)
But what about totally normal poop? Why is it brown? The answer is surprisingly straightforward and the team at the Today I Found Out YouTube channel is prepared to drop a knowledge log for you.
The short and skinny: The brown color is derived from "the bile in your gallbladder being metabolized by the bacteria in your intestines." The byproduct of that interaction colors your poop brown under ideal circumstances. Without that byproduct, your poop would have a sort of grayish white color.
That's why if your poop takes on that grayish white color, it's a good indication that you're having issues with bile production. Or maybe you ate a ghost.