Your S%$@ Can Be Silver, Newborns Don't Poop, and Other Things You Didn't Know About Feces
The act of pooping is a smelly subject, one we humans discreetly relegate to a small porcelain "chair." Atop this throne, locked behind closed doors, amidst the din of a bathroom fan, we do our business in private. Rarely a peep is spoken about poop in public, unless accompanied by inane fart noises. And this is unfortunate, because human feces, while repulsive in sight and smell, are incredibly fascinating!
Human excrement may be a waste product, but it's not altogether valueless. Molded and formed through digestion, feces are composed (PDF) primarily of water, but also of fibers, dead bacteria, fat, inorganic material, and undigested proteins. This mixture, when dried, contains approximately five calories per gram, so it's no wonder that dung sustains a vast world of organisms, including bacteria, fungi, and insects. Life dumps. Somebody's got to clean up the mess.
Human feces rarely reach fungi or insects, however. Instead, they are flushed away to sewage treatment facilities, where they can be feasted upon by colonies of aerobic bacteria housed in large silos. But before waste embarks upon the journey created by modern sanitation, it must first be excreted.
When leaving the anus, feces can come in all sorts of shapes and sizes depending upon the time spent within the large intestine. The type of stool can be very informative to physicians; that's why scientists have classified seven types of stools. They're outlined in the blush-worthy Bristol Stool Chart, seen below.
The typical human being poops about once per day, excreting approximately one ounce of waste for every twelve pounds of body weight. If the lifetime fruits of this regular labor were gathered and piled, the typical American would own a stinky mound weighing almost 27,000 pounds!
Most of this waste is just as you might picture it: brown, slimy, and smelly. But occasionally, human feces can take on some rather exotic hues. If one consumes Prussian blue to treat radiation poisoning, or imbibes exorbitant amounts of grape soda, then that individual may find himself or herself crapping blue. Stranger still, a blockage of the bile ducts -- often caused by gallstones -- coupled with gastrointestinal bleeding can produce stools of scintillating metallic silver.
Silver stools are shocking, but even more eye-opening (and unpalatable) is what comes out of the butts of newborn human babies. Surprise: it's actually not feces! Composed of the materials ingested by the baby from its time spent in the uterus -- often epithelial cells, mucus, amniotic fluid, and bile -- the substance is called meconium. Meconium has the sticky texture of tar, is olive green in hue, and is thankfully odorless. The same cannot be said for infants' later stools, however.
Blessedly, babies don't stay babies forever. But as soiled diapers give way to training potties, a rare condition called encopresis may manifest in which children develop a fear of pooping. There are a variety of treatment methods and a bounty of books available to help, sporting friendly titles like "The Gas We Pass: The Story of Farts," "I Can't, I Won't, No Way!", and the pithily-dubbed "Potty."
From its smell to the tacky humor it engenders, poop is something we all have to deal with. While we may not appreciate its looks, we can still acknowledge the fascinating science behind it.
(Images: 1. Bristol Chart by Kyle Thompson via Wikimedia Commons 2. Silver Stool by Herbert L. Fred, MD and Hendrik A. van Dijk via CNX)