Excerpts from Roger's World in the July '95 issue of Coast Weekly:
Here's the scoop on poop.
By Roger Luckenbach, PhD
"...Bodily functions - especially things that come out of us - seem to create
severe embarrassment. So we develop all manner of euphemisms to deal with
the topic. Feces probably has more pet names than any other word: caca, poop,
doo-doo, number two, BM (short for bowel movement), turds, to name a few. We
are even afraid to talk about animal dung, and instead employ all sorts of
silly phrases such as cow pies, goat berries and donkey apples.
Clinically, feces are composed largely of materials that could not be digested,
together with water, salts, mucus, cellular debris sloughed off from the
intestines and bacteria; the remainder is cellulose fiber and other roughage.
Because a large part of feces is not of dietary origin, feces continue to form and are passed even during prolonged starvation.
The brown color is derived from bile pigments, which are formed from dead red blood cells. The principle bile pigment is bilirubin, a breakdown product of
hemoglobin, which is filtered through the liver and then dumped via the gall bladder into the intestines. Consequently, hepatitis or gallstones may
alter fecal color, turning the stool grayish-brown. Anemia may also yield a yellowish appearance. On the other hand, a black-tarry stool is indicative
of gastrointestinal bleeding, while bright red color is indicative of hemorrhoidal bleeding. Various foods may also lend various hues, such as corn or beets.
The pungent odor of feces results from a cocktail of compounds produced by bacterial action upon residues. Odoriferous bacterial products include
indole, skatole, mercaptans, hydrogen sulfide, and ammonia. The most characteristic smell derives from indole and skatole, derived principally
from the digestion of the amino acid tryptophan. Specific nuances of odor depend upon an individual's colonic flora and the type of food eaten.
All humans harbor vast hordes of coprophilic (feces-loving) bacteria called E. coli. At any time we carry about seven pounds of bacteria, all
busily making gas. It is doubtful we would survive well without our symbiotic guests. E. coli. contributes vitamin K which is essential
for proper blood clotting. Additionally, significant amounts of vitamin B-12, thiamine and riboflavin are also produced. As an embarrassing byproduct, almost
a gallon of methane gas is also produced per day.
Bacterial flora varies not only from person to person, but also from region to
region. Some forms can kill or cause serious illness. Likewise, if they get into other parts of the body, such as the urinary tract, they can cause infections.
Food takes any where from 15 to 30 hours to pass through the entire system. This is called transit time and is strongly correlated to the amount of
roughage in the diet. Vegetarians have short ones; heavy meat eaters tend to be extreme. You can measure yours by simply eating a large serving of corn or red beets.
Once swallowed, food is sloshed and churned in the stomach for three to five hours, before being sent to the 20-some feet of the small intestine where it
spends another four to five hours. Most of the bacterial degrading is accomplished in the colon, where meals mash into each other and may merge for
an additional five to 25 hours.
An average person defecates some seven pounds per day. This amounts to a little
over a ton of feces per year. In nature, fungal and bacterial decomposers make quick work recycling it. Occasionally, cave conditions have provided rare
opportunities to fossilize ancient human feces. (Dinosaur coprolites, as fossil feces are called, also exist complete with casts of dung beetle workings).
Modern anthropologists have taken to examining ancient diets in hopes of finding former food sources, which are now neglected.
Feces may not yield enlightenment but they can provide insights."
Poopie in outer space?
Thanks to gravity, we here on earth take going to the
bathroom for granted, but using the toilet in space isn't
nearly as easy. For a long time, says NASA, astronauts
actually taped a plastic bag to their buttocks to collect
feces and used a hose-and-bag device to urinate.
Then, in the early 70s, NASA improved bathroom technology
with its vacuum toilet. To defecate, astronauts now sit on
this toilet and turn the vacuum on. Urination is done
through what looks like your vacuum cleaner's hose
attachment. Using this toilet is a bit tricky, so part of
the preparation for space travel includes potty training,
but it sure beats the old bag system.
Source: THE STRAIGHT DOPE column by Cecil Adams