Though there's no specific character mentioned, I envisioned Percy (I can picture him doing/saying almost anything) as the character in mind for this, but feel free to envision whoever you think suits this.

WARNING: LANGUAGE AND CRUDE, HUMORLESS HUMOR.

Enjoy. Read at your own risk :]

From within the boiling bowels of your intestines, each substantial meal undergoes a metamorphosis from the moment it enters your mouth. Hacked into bits and digested, it sustains you until... That deep rumbling from within the caged beast- your stomach converts every delicious morsel into: A big pile of shit. Wasted from the inside, and pushed through the out, its pungent scent only makes a momentary mark before it is engulfed in the wave of toilet bowl water, and eventually engulfed in all sorts. You can't help but feel relieved, until you're struck by a new thought: Did you wipe?

You sit on the toilet for so long, and when you get up, you glance down and see the shit you forgot to flush. You see the shit you forgot you even let out. And you're lucky, damn it, that you spared a look down because otherwise you would have been walking around with shit lodged up your ass. But doesn't it originate from inside of your ass? It's odd—no, not odd, facetious—because you sit on your bathroom floor with a can of Lysol next to you and actually ponder the question: where does your shit really come from?

It's crude.
My friend and I both contributed a paragraph to this.