Feces

This article is about feces in general. For specifically human feces, seeHuman feces.

"Dog poop" redirects here. For the 2005 incident, seeDog poop girl.

"Fecal matter" redirects here. For the American punk rock band, seeFecal Matter (band).

Not to be confused withmanure,faces,orfacies.

A comparison ofelephant(left) andhuman feces(right)

Feces(orfaeces;sg.:faex) are the solid or semi-solid remains of food that was not digested in thesmall intestine,and has been broken down by bacteria in thelarge intestine.Feces contain a relatively small amount ofmetabolic wasteproducts such as bacterially alteredbilirubin,and dead epithelial cells from the lining of the gut.

Feces are discharged through theanusorcloacaduringdefecation.

Feces can be used asfertilizerorsoil conditionerin agriculture. They can also be burned asfuelor dried and used forconstruction.Somemedicinaluses have been found. In the case ofhuman feces,fecal transplants orfecal bacteriotherapyare in use.Urineand feces together are calledexcreta.

Skatoleis the principal compound responsible for the unpleasant smell of feces.

Characteristics

Themoleculehydrogen sulfidecontributes to the smell of feces.

The distinctiveodorof feces is due toskatole,andthiols(sulfur-containing compounds), as well as amines and carboxylic acids. Skatole is produced fromtryptophanvia indoleacetic acid.Decarboxylationgives skatole.

The perceived bad odor of feces has been hypothesized to be a deterrent for humans, as consuming or touching it may result in sickness or infection.

Physiology

Main article:Defecation

Feces are discharged through theanusorcloacaduringdefecation.This process requires pressures that may reach 100 millimetres of mercury (3.9 inHg) (13.3 kPa) in humans and 450 millimetres of mercury (18 inHg) (60 kPa) in penguins.The forces required to expel the feces are generated through muscular contractions and a build-up of gases inside the gut, prompting the sphincter to relieve the pressure and release the feces.

Ecology

After an animal has digested eaten material, the remains of that material are discharged from its body as waste. Although it is lower in energy than the food from which it is derived, feces may retain 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 asdung beetles,who cansenseodors from long distances.Some may specialize in feces, while others may eat other foods. Feces serve not only as a basic food, but also as a supplement to the usual diet of some animals. This process is known ascoprophagia,and occurs in various animal species such as young elephants eating the feces of their mothers to gain essentialgut flora,or by other animals such as dogs, rabbits, and monkeys.

Feces and urine, which reflectultravioletlight, are important to raptors such askestrels,who can see thenear ultravioletand thus find their prey by theirmiddensandterritorialmarkers.

Seedsalso may be found in feces. Animals who eatfruitare known asfrugivores.An advantage for a plant in having fruit is that animals will eat the fruit and unknowingly disperse the seed in doing so. This mode ofseed dispersalis highly successful, as seeds dispersed around the base of a plant are unlikely to succeed and often are subject to heavypredation.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 that subsist on dead organic matter ordetritusare known asdetritivores,and play an important role in ecosystems by recycling organic matter back into a simpler form that plants and otherautotrophsmay absorb once again. This cycling of matter is known as thebiogeochemical cycle.To maintain nutrients in soil it is therefore important that feces returns 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

Main article:Human feces

Depending on the individual and the circumstances, human beings may defecate several times a day, every day, or once every two or three days. Extensive hardening of the feces that interrupts this routine for several days or more is calledconstipation.

The appearance of human fecal matter varies according to diet and health.Normally it is semisolid, with amucuscoating. A combination ofbileandbilirubin,which comes from deadred blood cells,gives feces the typical brown color.

After themeconium,the first stool expelled, a newborn's feces contains onlybile,which gives it a yellow-green color.Breast feedingbabies expel soft, pale yellowish, and not quite malodorous matter; but once the baby begins to eat, and the body starts expelling bilirubin from dead red blood cells, its matter acquires the familiar brown color.

At different times in their life, human beings will expel feces of different colors and textures. A stool that passes rapidly through the intestines will look greenish; lack of bilirubin will make the stool look like clay.

Uses of animal feces

See also:Reuse of excretaandHuman feces § Uses

Fertilizer

The feces of animals, e.g.guanoandmanure,often are used asfertilizer.

Energy

Further information:Dry animal dung fuel

Dry animal dung,such as that ofcamel,bisonandcattle,is burned as fuel in many countries.

Animals such as thegiant pandaandzebrapossess gut bacteria capable of producing biofuel. The bacterium in question,Brocadia anammoxidans,can be used to synthesize the rocket fuelhydrazine.

Coprolites and paleofeces

Acoproliteisfossilizedfeces and is classified as atrace fossil.Inpaleontologythey give evidence about the diet of an animal. They were first described byWilliam Bucklandin 1829. Prior to this, they were known as "fossilfir cones"and"bezoarstones ". They serve a valuable purpose in paleontology because they provide direct evidence of the predation and diet of extinct organisms.Coprolites may range in size from a few millimetres to more than 60 centimetres.

Palaeofecesare ancientfeces,often found as part ofarchaeologicalexcavations or surveys. Intact paleofeces of ancient people may be found in caves in arid climates and in other locations with suitable preservation conditions. These are studied to determine thedietandhealthof the people who produced them through the analysis of seeds, small bones, and parasite eggs found inside. Feces may contain information about the person excreting the material as well as information about the material. They also may be analyzed chemically for more in-depth information on the individual who excreted them, usinglipidanalysis and ancientDNAanalysis. The success rate of usable DNA extraction is relatively high in paleofeces, making it more reliable than skeletal DNA retrieval.

The reason this analysis is possible at all is due to the digestive system not being entirely efficient, in the sense that not everything that passes through the digestive system is destroyed. Not all of the surviving material is recognizable, but some of it is. Generally, this material is the best indicator archaeologists can use to determine ancient diets, as no other part of the archaeological record is so direct an indicator.

A process that preserves feces in a way that they may be analyzed later is theMaillard reaction.This reaction creates a casing of sugar that preserves the feces from the elements. To extract and analyze the information contained within, researchers generally have to freeze the feces and grind it up into powder for analysis.

Other uses

A pet waste station inTucker, Georgia,US

Animal dung occasionally is used as acementto makeadobe(mudbrick) huts,or even in throwing sports, especially with cow and camel dung.

Kopi luwak,or civet coffee, is coffee made from coffee beans that have been eaten and excreted byAsian palm civets(Paradoxurus hermaphroditus).

Giant pandasprovide fertilizer for the world's most expensivegreen tea.InMalaysia,tea is made from the droppings ofstick insectsfed onguavaleaves.

In northernThailand,elephantsare used to digest coffee beans in order to makeBlack Ivory coffee,which is among the world's most expensive coffees.Paperis also made from elephant dung in Thailand.Haathi Chaapis a brand of paper made from elephant dung.

Dogfeces was used in thetanningprocess ofleatherduring theVictorian era.Collected dog feces, known as "pure", "puer", or "pewer",were mixed with water to form a substance known as "bate", becauseproteolyticenzymesin the dog feces helped to relax the fibrous structure of the hide before the final stages of tanning.Dog feces collectors were known aspure finders.

Elephants,hippos,koalasand pandas are born with sterile intestines, and require bacteria obtained from eating the feces of their mothers to digest vegetation.

In India,cow dungandcow urineare major ingredients of the traditionalHindudrinkPanchagavya.PoliticianShankarbhai Vegadstated that they can curecancer.

Terminology

Cyclosia papilionarisconsuming bird droppings

Fecesis the scientific terminology, while the termstoolis also commonly used in medical contexts.Outside of scientific contexts, these terms are less common, with the most common layman's term beingpooporpoo.The termshitis also in common use, although it is widely considered vulgar or offensive. There are many other terms, see below.

Etymology

The wordfaecesis the plural of theLatinwordfaexmeaning "dregs". In most English-languageusage,there is no singular form, making the word aplurale tantum;out of various major dictionaries, only one entersvariation from plural agreement.

Synonyms

Further information:Shit

"Feces" is used more in biology and medicine than in other fields (reflectingscience's tradition of classical Latin andNeo-Latin)

• In hunting and tracking, terms such asdung,scat,spoor,anddroppingsnormally are used to refer to non-human animal feces
• In husbandry and farming,manureis common.
• Stoolis a common term in reference tohuman feces.For example, inmedicine,to diagnose the presence or absence of a medical condition, astool samplesometimes is requested for testing purposes.
• The termbowel movement(s)(with each movement a defecation event) is also common inhealth care.

There are many synonyms in informalregistersfor feces, just like there are forurine.Many areeuphemistic,colloquial,or both; some areprofane(such asshit), whereas most belong chiefly tochild-directed speech(such aspooor thepalindromic wordpoop) or tocrude humor(such ascrap,dump,loadandturd.).

Horsefeces

Feces of animals

The feces of animals often have special names (some of them are slang), for example:

• Non-human animals
  • 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
• Wildcarnivores– scat
• Otter–spraint
• Birds(individual) – droppings (also include urine as white crystals ofuric acid)
• Seabirdsorbats(large accumulations) –guano
• Herbivorousinsects,such ascaterpillarsandleaf beetles–frass
• Earthworms,lugwormsetc. –worm castings(feces extruded at ground surface)
• Feces when used asfertilizer(usually mixed with animal bedding and urine) –manure
• Horses– horse manure, roadapple (before motor vehicles became common, horse droppings were a big part of the rubbish communities needed to clean off roads)

Society and culture

Sign ordering owners to clean up after pets,Houston, Texas,2011

Feelings of disgust

Main article:Human feces

In all human cultures, feces elicit varying degrees ofdisgustin adults. Children under two years typically have no disgust response to it, suggesting it is culturally derived.Disgust toward feces appears to be strongest in cultures whereflush toiletsmake olfactory contact with human feces minimal.Disgust is experienced primarily in relation to the sense of taste (either perceived or imagined) and, secondarily to anything that causes a similar feeling by sense of smell, touch, or vision.

Social media

There is aPile of Poo emojirepresented inUnicodeasU+1F4A9💩PILE OF POO,calledunchiorunchi-kunin Japan.

Jokes

Poop is the center oftoilet humor,and is commonly an interest of young children and teenagers.

See also

• Coprophagia
• Coprophilia
• Coprophilous fungi
• Cow dung
• Excretory system
• Fecal microbiota
• Fecal plug
• Jenkem
• Manure
• Metabolic waste
• Night soil
• Sanitation
• Scatology
• Whale feces
• Zooplankton fecal pellets

External links

• Article on Feces– MedFriendly