Poop, and Kind of a Lot of It
You can be full of beans. Full of yourself. Full of ... well, you know. Poop. And kind of a lot of it, as it turns out.
When you eat and drink, your body only needs a few hours to extract the vitamins and nutrients it needs from that food, and the leftovers are (you guessed it!) off to be excreted. The intestines -- your bowels -- are made up of both the small and large intestine, plus your rectum. Your small intestine is a tube that's about 20 feet (6 meters) long and 1 inch (2.5 centimeters) in diameter, and your large intestine is also longer than you might expect, too: It's a tube about 5 feet (1.5 meters) long, and 3 inches (7.6 centimeters) in diameter. In total, that's about the length of a small, basic vinyl garden hose you'd use in your yard, and it's full of waste.
Your stool is made up of undigested food, but that's not all. There's also mucus, bacteria and dead cells in there -- and it's the combination of all these ingredients that make poop brown. A normal bowel movement is mostly water, though (about 75 percent of it), and most of us get rid of about 3 to 8 ounces of waste every day [source: Britannica]. (For comparison: An iPhone 5 weighs about 4 ounces [source: Apple].)