Who doo? You do.

**Disclaimer: This post is about poop.

A few days ago I stumbled upon this webpage and couldn’t stop laughing. I don’t think I have ever laughed so hard in my entire life. I was crying, a stitch in my side. Any time I would regain my composure, I would lose it again within 0.237 seconds of reading another line. So of course, after struggling through the page, I decided to consult my trusty friend YouTube for some poop-themed videos. Here’s one of my favorites: 3 Types of Girlfriends Based on Pooping Habits (it’s a little vulgar). Now, I’m not entirely sure why I find these types of things so entertaining, but I think I find them funny because they are usually true. Some people don’t like to admit they poop, and they definitely don’t want to talk about it, but why is that so? Everyone poops!

Have you ever wondered how poop is formed, or why it comes in different shapes and sizes? Well, let me enlighten you. After food passes through the mouth, esophagus, and stomach, being digested by various amylases and gastric juices, it makes its way into the small intestine where the majority of the fluid and nutrients from the digestive process and from the food you eat are reabsorbed by the body. An additional amount of fluid is reabsorbed in the large intestine, also known as the colon.

This is where the magic happens.

Digested food moves through the colon via a type of smooth muscle contraction called peristalsis. As it moves along, the poop starts to take shape as the fluid (referred to as H2O in the diagram below) is drawn out. As more fluid leaves, the poop becomes more solid. During times of viral or bacterial infections, fluid may not be properly reabsorbed, causing the common side effect of diarrhea. Have you ever been constipated? This is a result of poop moving too slowly through the colon, causing too much fluid to be reabsorbed. Depending on what you eat, your poop may vary in appearance. If you eat some corn, you may see it again since our bodies can’t digest the cellulose outer layer. Ever drink a brightly colored slushy saturated with food coloring? Your poop likely changed color.

The digestive tracts of carnivores differ from those of herbivores due to the different digestive requirements each type of animal has. Take a koala for example, whose cecum (the section of colon below the attachment point of the small intestine) is about 2 meters long! This longer cecum enables the koalas to digest leaves and provides a greater amount of surface area for nutrients to be absorbed. Check out this koala who, instead of eating leaves, is chomping on an apple. I wonder how long it took for that apple to become poop…

Sources:

Campbell, Neil A., and Jane B. Reece. Biology. San Francisco: Benjamin Cummings, 2002. Print.