Yes, in fact – can you believe it – girls behave like actual human beings. As to why, the body is fairly adept at taking the nutrients it needs from food, but there’s always stuff left over. Without pooping, things would get pretty uncomfortable pretty fast.
Why is my poop brown and stinky?
Bile from the gall bladder (which helps break up fat) mixes with everything else to impart the usual brown hue, though other colors are certainly possible as well (See bit.ly/PooColors for details). The stink is down to compounds like hydrogen sulfide, indoles, and the appropriately named scatols. See: bit.ly/PooSmell