Feces (or faeces; sg.: faex) are the solid or semi-solid remains of food that was not digested in the small intestine, and has been broken down by bacteria in the large intestine. [1] [2] Feces contain a relatively small amount of metabolic waste products such as bacterially altered bilirubin, and dead epithelial cells from the lining of the gut. [1]
Feces are discharged through the anus or cloaca during defecation.
Feces can be used as fertilizer or soil conditioner in agriculture. They can also be burned as fuel or dried and used for construction. Some medicinal uses have been found. In the case of human feces, fecal transplants or fecal bacteriotherapy are in use. Urine and feces together are called excreta.
The distinctive odor of feces is due to skatole, and thiols (sulfur-containing compounds), as well as amines and carboxylic acids. Skatole is produced from tryptophan via indoleacetic acid. Decarboxylation gives skatole. [3] [4]
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. [5]
Feces are discharged through the anus or cloaca during defecation. 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. [6] [7] 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. [7]
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. [8] 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, who can sense odors from long distances. [9] 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 as coprophagia, and occurs in various animal species such as young elephants eating the feces of their mothers 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, who can see the near ultraviolet and thus find their prey by their middens and territorial markers. [10]
Seeds also may be found in feces. Animals who eat fruit are known as frugivores. 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 of seed dispersal is highly successful, as seeds dispersed around the base of a plant are unlikely to succeed and often are 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 that 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 that plants and other autotrophs may absorb once again. This cycling of matter is known as the biogeochemical 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.
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 called constipation.
The appearance of human fecal matter varies according to diet and health. [11] Normally it is semisolid, with a mucus coating. A combination of bile and bilirubin, which comes from dead red blood cells, gives feces the typical brown color. [1] [2]
After the meconium, the first stool expelled, a newborn's feces contains only bile, which gives it a yellow-green color. Breast feeding babies 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. [2]
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.
The feces of animals, e.g. guano and manure, often are used as fertilizer. [12]
Dry animal dung, such as that of camel, bison and cattle, is burned as fuel in many countries. [13]
Animals such as the giant panda [14] and zebra [15] possess gut bacteria capable of producing biofuel. The bacterium in question, Brocadia anammoxidans, can be used to synthesize the rocket fuel hydrazine. [16] [17]
A coprolite is fossilized feces and is classified as a trace fossil. In paleontology they give evidence about the diet of an animal. They were first described by William Buckland in 1829. Prior to this, they were known as "fossil fir cones" and "bezoar stones". They serve a valuable purpose in paleontology because they provide direct evidence of the predation and diet of extinct organisms. [18] Coprolites may range in size from a few millimetres to more than 60 centimetres.
Palaeofeces are ancient feces, often found as part of archaeological excavations 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 the diet and health of 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, using lipid analysis and ancient DNA analysis. The success rate of usable DNA extraction is relatively high in paleofeces, making it more reliable than skeletal DNA retrieval. [19]
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. [20]
A process that preserves feces in a way that they may be analyzed later is the Maillard 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. [21]
Animal dung occasionally is used as a cement to make adobe (mudbrick) huts, [22] or even in throwing sports, especially with cow and camel dung. [23]
Kopi luwak, or civet coffee, is coffee made from coffee beans that have been eaten and excreted by Asian palm civets (Paradoxurus hermaphroditus). [24]
Giant pandas provide fertilizer for the world's most expensive green tea. [25] In Malaysia, tea is made from the droppings of stick insects fed on guava leaves.
In northern Thailand, elephants are used to digest coffee beans in order to make Black Ivory coffee, which is among the world's most expensive coffees. Paper is also made from elephant dung in Thailand. [25] Haathi Chaap is a brand of paper made from elephant dung.
Dog feces was used in the tanning process of leather during the Victorian era. Collected dog feces, known as "pure", "puer", or "pewer", [26] were mixed with water to form a substance known as "bate", because proteolytic enzymes in the dog feces helped to relax the fibrous structure of the hide before the final stages of tanning. [27] Dog feces collectors were known as pure finders. [28]
Elephants, hippos, koalas and pandas are born with sterile intestines, and require bacteria obtained from eating the feces of their mothers to digest vegetation.
In India, cow dung and cow urine are major ingredients of the traditional Hindu drink Panchagavya . Politician Shankarbhai Vegad stated that they can cure cancer. [29]
Feces is the scientific terminology, while the term stool is also commonly used in medical contexts. [30] Outside of scientific contexts, these terms are less common, with the most common layman's term being poop or poo. The term shit is also in common use, although it is widely considered vulgar or offensive. There are many other terms, see below.
The word faeces is the plural of the Latin word faex meaning "dregs". In most English-language usage, there is no singular form, making the word a plurale tantum; [31] out of various major dictionaries, only one enters variation from plural agreement. [32]
"Feces" is used more in biology and medicine than in other fields (reflecting science's tradition of classical Latin and Neo-Latin)
There are many synonyms in informal registers for feces, just like there are for urine. Many are euphemistic, colloquial, or both; some are profane (such as shit ), whereas most belong chiefly to child-directed speech (such as poo or the palindromic word poop) or to crude humor (such as crap, dump, load and turd.).
The feces of animals often have special names (some of them are slang), for example:
In all human cultures, feces elicit varying degrees of disgust in adults. Children under two years typically have no disgust response to it, suggesting it is culturally derived. [34] Disgust toward feces appears to be strongest in cultures where flush toilets make olfactory contact with human feces minimal. [35] [36] 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.
There is a Pile of Poo emoji represented in Unicode as U+1F4A9💩PILE OF POO, called unchi or unchi-kun in Japan. [37] [38]
Poop is the center of toilet humor, and is commonly an interest of young children and teenagers. [39]
Coprophagia or coprophagy is the consumption of feces. The word is derived from the Ancient Greek κόπρος kópros "feces" and φαγεῖν phageîn "to eat". Coprophagy refers to many kinds of feces-eating, including eating feces of other species (heterospecifics), of other individuals (allocoprophagy), or one's own (autocoprophagy) – those once deposited or taken directly from the anus.
Panchagavya or panchakavyam is a mixture used in traditional Hindu rituals that is prepared by mixing five ingredients. The three direct constituents are cow dung, urine, and milk; the two derived products are curd and ghee. These are mixed and then allowed to ferment. The Sanskrit word panchagavya means "five cow-derivatives". When used in Ayurvedic medicine, it is also called cowpathy.
Skatole or 3-methylindole is an organic compound belonging to the indole family. It occurs naturally in the feces of mammals and birds and is the primary contributor to fecal odor. In low concentrations, it has a flowery smell and is found in several flowers and essential oils, including those of orange blossoms, jasmine, and Ziziphus mauritiana. It has also been identified in certain cannabis varieties.
A coprolite is fossilized feces. Coprolites are classified as trace fossils as opposed to body fossils, as they give evidence for the animal's behaviour rather than morphology. The name is derived from the Greek words κόπρος and λίθος. They were first described by William Buckland in 1829. Before this, they were known as "fossil fir cones" and "bezoar stones". 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 over 60 centimetres.
Kopi luwak, also known as civet coffee, is a coffee that consists of partially digested coffee cherries, which have been eaten and defecated by the Asian palm civet. The cherries are fermented as they pass through a civet's intestines, and after being defecated with other fecal matter, they are collected. Asian palm civets are increasingly caught in the wild and traded for this purpose.
Cow dung, also known as cow pats, cow pies, cow poop or cow manure, is the waste product (faeces) of bovine animal species. These species include domestic cattle ("cows"), bison ("buffalo"), yak, and water buffalo. Cow dung is the undigested residue of plant matter which has passed through the animal's gut. The resultant faecal matter is rich in minerals. Color ranges from greenish to blackish, often darkening soon after exposure to air.
Organic fertilizers are fertilizers that are naturally produced. Fertilizers are materials that can be added to soil or plants, in order to provide nutrients and sustain growth. Typical organic fertilizers include all animal waste including meat processing waste, manure, slurry, and guano; plus plant based fertilizers such as compost; and biosolids. Inorganic "organic fertilizers" include minerals and ash. The organic-mess refers to the Principles of Organic Agriculture, which determines whether a fertilizer can be used for commercial organic agriculture, not whether the fertilizer consists of organic compounds.
A pooper-scooper, or poop scoop, is a device used to pick up animal feces from public places and yards, particularly those of dogs. Pooper-scooper devices often have a bag or bag attachment. 'Poop bags' are alternatives to pooper scoopers, and are simply a bag, usually turned inside out, to carry the feces to a proper disposal area. Sometimes, the person performing the cleanup is also known as the pooper-scooper.
Fecal microbiota transplant (FMT), also known as a stool transplant, is the process of transferring fecal bacteria and other microbes from a healthy individual into another individual. FMT is an effective treatment for Clostridioides difficile infection (CDI). For recurrent CDI, FMT is more effective than vancomycin alone, and may improve the outcome after the first index infection.
A civet is a small, lean, mostly nocturnal mammal native to tropical Asia and Africa, especially the tropical forests. The term civet applies to over a dozen different species, mostly from the family Viverridae. Most of the species's diversity is found in southeast Asia. Civets do not form a monophyletic group, as they consist only of certain members of the Viverridae, Eupleridae, and Nandiniidae.
Human feces are the solid or semisolid remains of food that could not be digested or absorbed in the small intestine of humans, but has been further broken down by bacteria in the large intestine. It also contains bacteria and a relatively small amount of metabolic waste products such as bacterially altered bilirubin, and the dead epithelial cells from the lining of the gut. It is discharged through the anus during a process called defecation.
Chicken manure is the feces of chickens used as an organic fertilizer, especially for soil low in nitrogen. Of all animal manures, it has the highest amount of nitrogen, phosphorus, and potassium. Chicken manure is sometimes pelletized for use as a fertilizer, and this product may have additional phosphorus, potassium or nitrogen added. Optimal storage conditions for chicken manure include keeping it in a covered area and retaining its liquid, because a significant amount of nitrogen exists in the urine.
Manure is organic matter that is used as organic fertilizer in agriculture. Most manure consists of animal feces; other sources include compost and green manure. Manures contribute to the fertility of soil by adding organic matter and nutrients, such as nitrogen, that are utilised by bacteria, fungi and other organisms in the soil. Higher organisms then feed on the fungi and bacteria in a chain of life that comprises the soil food web.
Uguisu no fun, also called the "Geisha Facial", refers to the excrement produced by a particular nightingale, the Japanese bush warbler. The droppings have been used in facials throughout Japanese history. Recently, the product has appeared in the Western world. The facial is said to whiten the skin and balance skin tone, as well as treat skin affected by hyperpigmentation.
Dry dung fuel is animal feces that has been dried in order to be used as a fuel source. It is used in many countries. Using dry manure as a fuel source is an example of reuse of excreta. A disadvantage of using this kind of fuel is increased air pollution.
Liquid manure is a mixture of animal waste and organic matter used as an agricultural fertilizer, sometimes thinned with water. It can be aged in a slurry pit to concentrate it.
Whale feces, the excrement of whales, has a vital role in the ecology of oceans, earning whales the title of "marine ecosystem engineers." This significant ecological role stems from the nutrients and compounds found in whale feces, which have far-reaching effects on marine life.
Reuse of human excreta is the safe, beneficial use of treated human excreta after applying suitable treatment steps and risk management approaches that are customized for the intended reuse application. Beneficial uses of the treated excreta may focus on using the plant-available nutrients that are contained in the treated excreta. They may also make use of the organic matter and energy contained in the excreta. To a lesser extent, reuse of the excreta's water content might also take place, although this is better known as water reclamation from municipal wastewater. The intended reuse applications for the nutrient content may include: soil conditioner or fertilizer in agriculture or horticultural activities. Other reuse applications, which focus more on the organic matter content of the excreta, include use as a fuel source or as an energy source in the form of biogas.
Omni processor is a term coined in 2012 by staff of the Water, Sanitation, Hygiene Program of the Bill & Melinda Gates Foundation to describe a range of physical, biological or chemical treatments to remove pathogens from human-generated fecal sludge, while simultaneously creating commercially valuable byproducts. Air from feces are separated from common air, then these collected air from feces are compressed like (LPG) and used as fuel. An omni processor mitigates unsafe methods in developing countries of capturing and treating human waste, which annually result in the spread of disease and the deaths of more than 1.5 million children.
The Shit Museum is a museum in the province of Piacenza, in the north of Italy, and is reported to be the world's first museum dedicated to feces. The museum opened on 5 May 2015, having been founded by agricultural businessman Gianantonio Locatelli and three associates.