Feces



Feces, faeces, or fæces (see spelling differences) is a waste product from an animal's digestive tract expelled through the anus or cloaca during defecation.

Etymology
The word faeces is the plural of the Latin word fæx meaning "dregs". There is no singular form in the English language, making it a plurale tantum. There are many colloquial terms for feces, of which some are considered profanity (such as shit and crap) while others (such as poo, poop, number two, doodoo, dookie and doody) are not. Terms such as dung, scat, spoor and droppings are normally used to refer to animal feces.

Stool is a common term normally used in reference to human feces. For example, in medicine to diagnose the presence or absence of a medical condition, a stool sample is sometimes requested for testing purposes. The term "stool" can also be used for that of non-human species.

Ecology
After an animal has digested eaten material, the remains of that material are expelled from its body as waste. Though it is lower in energy than the food it came from, feces may still contain a large amount of energy, often 50% of that of the original food. This means that of all food eaten, a significant amount of energy remains for the decomposers of ecosystems. Many organisms feed on feces, from bacteria to fungi to insects such as dung beetles, which can sense odors from long distances. Some may specialize in feces, while others may eat other foods as well. Feces serve not only as a basic food, but also a supplement to the usual diet of some animals. This is known as coprophagia, and occurs in various animal species such as young elephants eating their mother's feces to gain essential gut flora, or by other animals such as dogs, rabbits, and monkeys.

Feces and urine, which reflect ultraviolet light, are important to raptors such as Kestrels, which are able to locate their prey by their middens and territorial markers.

Seeds may also be found in feces. Animals which eat fruit are known as frugivores. The advantage for a plant in having fruit is that animals will eat the fruit and unknowingly disperse the seed in doing so. This mode of seed dispersal is highly successful, as seeds dispersed around the base of a plant are unlikely to succeed and are often subject to heavy predation. Provided the seed can withstand the pathway through the digestive system, it is not only likely to be far away from the parent plant, but is even provided with its own fertilizer.

Organisms which subsist on dead organic matter or detritus are known as detritivores, and play an important role in ecosystems by recycling organic matter back into a simpler form which plants and other autotrophs may once again absorb. This cycling of matter is known as the biogeochemical cycle. To maintain nutrients in soil it is therefore important that feces return to the area from which they came, which is not always the case in human society where food may be transported from rural areas to urban populations and then feces disposed of into a river or sea.

Human feces
In humans, defecation may occur (depending on the individual and the circumstances) from once every two or three days to several times a day. Extensive hardening of the feces may cause prolonged interruption in the routine and is called constipation.

Human fecal matter varies significantly in appearance, depending on diet and health. Normally it is semisolid, with a mucus coating. Its brown coloration comes from a combination of bile and bilirubin, which comes from dead red blood cells.

In newborn babies, fecal matter is initially yellow/green after the meconium. This coloration comes from the presence of bile alone. In time, as the body starts expelling bilirubin from dead red blood cells, it acquires its familiar brown appearance, unless the baby is breast feeding, in which case it remains soft, pale yellowish, and not completely malodorous until the baby begins to eat significant amounts of other food.

Throughout the life of an ordinary human, one may experience many types of feces. A "green" stool is from rapid transit of feces through the intestines (or the consumption of certain blue or green food dyes in quantity), and "clay-like" appearance to the feces is the result of a lack of bilirubin.

Bile overload is very rare, and not a health threat. Problems as simple as serious diarrhea can cause blood in one's stool. Black stools caused by blood usually indicate a problem in the intestines (the black is digested blood), whereas red streaks of blood in stool are usually caused by bleeding in the rectum or anus.

Food may sometimes make an appearance in the feces. Common undigested foods found in human feces are seeds, nuts, corn and beans, mainly because of their high dietary fiber content. Beets may turn feces different hues of red. Artificial food coloring in some processed foods such as highly colorful packaged breakfast cereals can also cause unusual feces coloring if eaten in sufficient quantities.

Laboratory examination of feces, usually termed as stool examination or stool test, is done for the sake of diagnosis, for example, to detect presence of parasites such as pinworms and/or their eggs (ova) or to detect disease spreading bacteria.

Personal hygiene
All cultures practice some form of personal cleansing after expelling feces.
 * In Western and East Asian society, the use of toilet paper is widespread. Other paper products were also used before the advent of flush toilets.
 * Today some Western companies market toilet tissue or wipes for babies and campers.
 * In some European countries, the use of a bidet for additional cleaning is common.
 * In South Asia and Southeast Asia, showers are provided for use in toilets.
 * In Islam, washing of the anus with water is part of the prescribed ritual ablutions.
 * In India, the anus is also washed with water using the left hand. As with all such practices, hand washing after use of the toilet has become a very important public health concern.
 * In the United Kingdom, the Indian toilet was adapted as the WC or water closet and widely deployed in England during the reign of Queen Victoria. London suffered numerous outbreaks of food poisoning resulting from workers handling food after using the toilet. Cleansing of the anus was an arbitrary practice left to personal choice and facilities available.
 * In Ancient Rome, a communal sponge was employed. It was rinsed in a bucket of salt water after use.
 * In Japan, flat sticks were used in ancient times, being replaced by toilet paper as the country became more Westernized. Toilets that include built-in bidets have now become widely popular in private homes; these can be very sophisticated appliances, allowing users to adjust the temperature, direction and force of water jets, and offering warm air to dry the anus and surrounding regions. The toilet flushes automatically when the buttocks leave the seat.

Bristol Stool Scale
Consistency and shape of stools may be classified medically according to the Bristol Stool Scale.

Pica, a disorder where non-food items are eaten, can cause unusual stool.

Intestinal parasites and their ova (eggs) can sometimes be visible to the naked eye.

Odor
The distinctive odor of feces is due to bacterial action. Gut flora produce compounds such as indole, skatole, and thiols (sulfur-containing compounds), as well as the inorganic gas hydrogen sulfide. These are the same compounds that are responsible for the odor of flatulence. Consumption of foods with spices may result in the spices being undigested and adding to the odor of feces. The perceived bad odor of feces has been hypothesized to be a deterrent for humans, as consumption or touching it may result in sickness or infection. Of course, human perception of the odor is a subjective matter; an animal that eats feces may be attracted to its odor.

Pets
Pets can be trained to use litter boxes or wait to be allowed outside and defecate there. Training can be done in several ways, especially dependent on species. An example is crate training for dogs. Several companies market carpet cleaning products aimed at pet owners.

Uses
Human feces may be used as fertilizer (See also: Humanure) in the form of biosolids (treated sewage sludge). The feces of animals are often used as fertilizer; see manure and guano. Some animal feces, especially those of camel, bison and cattle, is used as fuel when dried out. Animal dung, besides being used as fuel, is occasionally used as a cement to make adobe mudbrick huts or even in throwing sports such as cow pat throwing or camel dung throwing contests. Kopi Luwak (pronounced ), or Civet coffee, is coffee made from coffee berries which have been eaten by and passed through the digestive tract of the Asian Palm Civet (Paradoxurus hermaphroditus).

See also Fewmets for the use of feces in venery, or Hunting in the Middle Ages, and Kumalak for the use of feces in fortune-telling in Central Asia.

Dog feces were used in the tanning process of leather during the Victorian era. Collected dog feces were mixed with water to form a substance known as "bate". Enzymes in the dog feces helped to relax the fibrous structure of the hide before the final stages of tanning.

Animal feces
The feces of animals often have special names. For example:
 * Non-human animals generally –
 * As bulk material – dung
 * Individually – droppings
 * Cattle –
 * Bulk material – cow dung
 * Individual droppings – cow pats, meadow muffins etc.
 * Deer (and formerly other quarry animals) – fewmets.
 * Wild carnivores – scat.
 * Otter – spraint.
 * Birds (individual) – droppings (also include urine as white crystals of uric acid).
 * Seabirds or bats (large accumulations) – guano.
 * Herbivorous insects, such as caterpillars and leaf beetles – frass.
 * Earthworms, lugworms etc. – worm castings (feces extruded at ground surface).
 * Feces when used as fertilizer (usually mixed with animal bedding and urine) – manure.
 * Horses – horse manure, roadapple.