Posted: Apr 28, 2017 7:48 pm
by Animavore
An elephant’s rectum is about 10 times longer than a cat’s, yet they poop in the same amount of time. This conundrum may not have stumped you—or even occurred to you—but it vexed researchers at Georgia Tech. “How do animals defecate at a constant duration?,” they quite literally asked in their paper—which by the way was published in the journal Soft Matter. “To answer this question, we begin with measurements of feces.”

So let’s begin.

As with every good scientific endeavor, they started by defining their variables. Defecation begins, for example, at t=0, which they say is “when the tip of feces appears.” They provided four separate videos just in case you weren’t sure exactly when that is. And to avoid confusion between “steady state” pooping, which is what humans do, and animals like rabbits that produce little pellets they restricted their study to cylindrical feces. Repeat: you will not learn anything about the pelleted feces of a rabbit in this article.

“But what size were these feces?” you’re almost definitely not wondering. The length of one fecal piece is equal to the length of the rectum. Don’t ask how they got that second measurement.

It’s not just the size of the feces in the animal, though (nor is it the size of the animal in the feces). It’s about the mucus. Yes—the mucus. You thought this was just going to be gross because of the poop factor, didn’t you? Well, now there’s mucus.

Mucus is an integral part of a bowel movement. It has a certain thickness and viscosity, both of which these researchers quantified and both of which scale with the size of the animal. That’s right. A mouse has a tiny (some might even say adorable) layer of mucus inside their rectum and an elephant has—well, you can probably picture it. All that slimy goodness helps move a turd along the digestive tract and out, which requires significant pressure from your rectum. See, you may not realize this, but the diameter of your poop matches the diameter of your rectum, which implies that feces aren’t squeezed out like toothpaste from a tube but rather slide out “similar to a sled sliding down a chute.”

Some more bathroom reading here.