Feces

{{Short description|Solid or semisolid remains of undigested food}} {{Hatnote group| {{For|specifically the human waste|human feces}} {{Redirect-several|dab=no|Poo (disambiguation)|Poo poo (disambiguation)|Fecal Matter (band)}} }} {{Distinguish|face{{!}}faces|facies}} {{pp|small=yes}} {{pp-move}} {{Use dmy dates|date=March 2021}} {{Multiple image | image1 = Elephant feces in the wildlife.jpg | width1 = 192 | alt1 = Elephant feces | image2 = Cow dung.JPG | width2 = 175 | alt2 = Cow feces | footer_align = center | footer = A comparison of elephant (left) and cow feces (right) }}

'''Feces''' (also '''faeces''' or '''fæces''') 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.<ref name=tortora1>{{cite book |last1=Tortora |first1=Gerard J. |last2=Anagnostakos |first2=Nicholas P. |title=Principles of anatomy and physiology |url=https://archive.org/details/principlesofanat05tort |url-access=registration |page=[https://archive.org/details/principlesofanat05tort/page/624 624] |edition=Fifth |location=New York |publisher=Harper & Row, Publishers |date=1987 |isbn=978-0-06-350729-6}}</ref><ref name=ciba>{{cite book |last1=Diem |first1=K. |last2=Lentner |first2=C. |chapter=Faeces |title=in: Scientific Tables |edition=Seventh |location=Basle, Switzerland |publisher=CIBA-GEIGY Ltd. |date=1970 |pages=657–660}}</ref> 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.<ref name=tortora1 />

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. {{TOC limit|3}}

==Characteristics== [[File:Hydrogen-sulfide-3D-vdW.png|right|thumb|100px|The molecule hydrogen sulfide contributes to the smell of feces.]] 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.<ref>{{cite journal |last1=Whitehead |first1=T. R. |last2=Price |first2=N. P. |last3=Drake |first3=H. L. |last4=Cotta |first4=M. A. |title=Catabolic pathway for the production of skatole and indoleacetic acid by the acetogen Clostridium drakei, Clostridium scatologenes, and swine manure |journal=Applied and Environmental Microbiology |volume=74 |issue=6 |pages=1950–3 |pmid=18223109 |pmc=2268313 |date=25 January 2008 |doi=10.1128/AEM.02458-07 |bibcode=2008ApEnM..74.1950W|issn = 0099-2240}}</ref><ref>{{cite journal |doi=10.1093/ajcn/32.1.173 |pmid=367144 |title=Microbial metabolites of tryptophan in the intestinal tract with special reference to skatole |journal=The American Journal of Clinical Nutrition |volume=32 |issue=1 |pages=173–178 |year=1979 |last1=Yokoyama |first1=M. T. |last2=Carlson |first2=J. R.|doi-access=free }}</ref>

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.<ref>{{cite journal |vauthors=Curtis V, Aunger R, Rabie T |title=Evidence that disgust evolved to protect from risk of disease |journal=Proc. Biol. Sci. |volume=271 |issue=Suppl 4 |pages=S131–3 |date=May 2004 |pmid=15252963 |pmc=1810028 |doi=10.1098/rsbl.2003.0144 |bibcode=2004PBioS.271.0144C }}</ref>

===Physiology=== {{Main|Defecation}} Feces are discharged through the anus or cloaca during defecation. This process requires pressures that may reach {{convert|100|mmHg|inHg}} (13.3 kPa) in humans and {{convert|450|mmHg|inHg}} (60 kPa) in penguins.<ref name="LangleyCheraskin1958">{{cite book |last1=Langley |first1=Leroy Lester |last2=Cheraskin |first2=Emmanuel |title=The Physiology of Man |url=https://books.google.com/books?id=aPFGAAAAYAAJ |year=1958 |publisher=McGraw-Hill |access-date=3 December 2019 |archive-date=1 August 2020 |archive-url=https://web.archive.org/web/20200801131456/https://books.google.com/books?id=aPFGAAAAYAAJ |url-status=live}}</ref><ref name="Meyer-RochowGal2003">{{cite journal |last1=Meyer-Rochow |first1=Victor Benno |last2=Gal |first2=Jozsef |title=Pressures produced when penguins pooh?calculations on avian defaecation |journal=Polar Biology |volume=27 |issue=1 |year=2003 |pages=56–58 |issn=0722-4060 |doi=10.1007/s00300-003-0563-3 |bibcode=2003PoBio..27...56M |s2cid=43386022}}</ref> 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.<ref name="Meyer-RochowGal2003" />

==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.<ref name="CummingsCampbell2008">{{cite book |last1=Cummings |first1=Benjamin |last2=Campbell |first2=Neil A. |title=Biology, 8th Edition, Campbell & Reece, 2008: Biology |url=https://books.google.com/books?id=5nZlDwAAQBAJ&pg=PA890 |edition=8th |year=2008 |publisher=Pearson |page=890 }}{{Dead link|date=April 2024 |bot=InternetArchiveBot |fix-attempted=yes }}</ref> 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.<ref>{{cite journal |doi=10.1038/scientificamerican1179-146 |vauthors=Heinrich B, Bartholomew GA |title=The ecology of the African dung beetle |journal=Scientific American |volume=241 |issue=5 |pages=146–56 |year=1979 |bibcode=1979SciAm.241e.146H}}</ref> 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.<ref>{{cite web |url=http://www.ci.manhattan.ks.us/DocumentView.aspx?DID=6468 |title=Document: Krestel |publisher=City of Manhattan, Kansas |access-date=11 February 2012}}{{dead link|date=March 2018 |bot=InternetArchiveBot |fix-attempted=yes }}</ref>

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.

== Environmental impacts ==

=== Fecal resistome === The "fecal resistome" refers to the entire gene pool found in human and animal feces responsible for conferring antimicrobial resistance.<ref name=":0">{{Cite journal |last1=Macedo |first1=Gonçalo |last2=van Veelen |first2=H. Pieter J. |last3=Hernandez-Leal |first3=Lucia |last4=van der Maas |first4=Peter |last5=Heederik |first5=Dick |last6=Mevius |first6=Dik |last7=Bossers |first7=Alex |last8=Schmitt |first8=Heike |date=2021 |title=Targeted metagenomics reveals inferior resilience of farm soil resistome compared to soil microbiome after manure application |url=https://linkinghub.elsevier.com/retrieve/pii/S0048969721004678 |journal=Science of the Total Environment |language=en |volume=770 |article-number=145399 |doi=10.1016/j.scitotenv.2021.145399 |pmid=33736375 |bibcode=2021ScTEn.77045399M }}</ref><ref>{{Cite journal |last1=Ma |first1=Tao |last2=McAllister |first2=Tim A. |last3=Guan |first3=Le Luo |date=2021 |title=A review of the resistome within the digestive tract of livestock |journal=Journal of Animal Science and Biotechnology |language=en |volume=12 |issue=1 |pages=121 |doi=10.1186/s40104-021-00643-6 |doi-access=free |issn=2049-1891 |pmc=8588621 |pmid=34763729}}</ref> Antibiotics taken by humans and animals primarily leave the body through feces and urine, which contain antibiotic resistance genes (ARGs) that act as an environmental pollutant.<ref>{{Cite journal |last1=Roose-Amsaleg |first1=Céline |last2=Laverman |first2=Anniet M. |date=2016 |title=Do antibiotics have environmental side-effects? 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Joakim |last2=Flach |first2=Carl-Fredrik |date=2022 |title=Antibiotic resistance in the environment |journal=Nature Reviews Microbiology |language=en |volume=20 |issue=5 |pages=257–269 |doi=10.1038/s41579-021-00649-x |issn=1740-1534 |pmc=8567979 |pmid=34737424}}</ref><ref>{{Cite journal |last1=Heuer |first1=Holger |last2=Smalla |first2=Kornelia |date=2007 |title=Manure and sulfadiazine synergistically increased bacterial antibiotic resistance in soil over at least two months |url=https://sfamjournals.onlinelibrary.wiley.com/doi/10.1111/j.1462-2920.2006.01185.x |journal=Environmental Microbiology |language=en |volume=9 |issue=3 |pages=657–666 |doi=10.1111/j.1462-2920.2006.01185.x |pmid=17298366 |bibcode=2007EnvMi...9..657H |issn=1462-2912|url-access=subscription }}</ref> These contaminants spread throughout the environment via agricultural processes, such as manure application, and human wastewater systems.<ref name=":1">{{Cite journal |last1=Berendonk |first1=Thomas U. |last2=Manaia |first2=Célia M. |last3=Merlin |first3=Christophe |last4=Fatta-Kassinos |first4=Despo |last5=Cytryn |first5=Eddie |last6=Walsh |first6=Fiona |last7=Bürgmann |first7=Helmut |last8=Sørum |first8=Henning |last9=Norström |first9=Madelaine |last10=Pons |first10=Marie-Noëlle |last11=Kreuzinger |first11=Norbert |last12=Huovinen |first12=Pentti |last13=Stefani |first13=Stefania |last14=Schwartz |first14=Thomas |last15=Kisand |first15=Veljo |date=2015 |title=Tackling antibiotic resistance: the environmental framework |url=https://www.nature.com/articles/nrmicro3439 |journal=Nature Reviews Microbiology |language=en |volume=13 |issue=5 |pages=310–317 |doi=10.1038/nrmicro3439 |pmid=25817583 |issn=1740-1526|url-access=subscription }}</ref><ref>{{Cite journal |last1=Rizzo |first1=L. |last2=Manaia |first2=C. |last3=Merlin |first3=C. |last4=Schwartz |first4=T. |last5=Dagot |first5=C. |last6=Ploy |first6=M.C. |last7=Michael |first7=I. |last8=Fatta-Kassinos |first8=D. |date=2013 |title=Urban wastewater treatment plants as hotspots for antibiotic resistant bacteria and genes spread into the environment: A review |url=https://linkinghub.elsevier.com/retrieve/pii/S0048969713000429 |journal=Science of the Total Environment |language=en |volume=447 |pages=345–360 |doi=10.1016/j.scitotenv.2013.01.032 |bibcode=2013ScTEn.447..345R |url-access=subscription }}</ref><ref>{{Cite journal |last1=Zhu |first1=Yong-Guan |last2=Zhao |first2=Yi |last3=Li |first3=Bing |last4=Huang |first4=Chu-Long |last5=Zhang |first5=Si-Yu |last6=Yu |first6=Shen |last7=Chen |first7=Yong-Shan |last8=Zhang |first8=Tong |last9=Gillings |first9=Michael R. |last10=Su |first10=Jian-Qiang |date=2017 |title=Continental-scale pollution of estuaries with antibiotic resistance genes |url=https://www.nature.com/articles/nmicrobiol2016270 |journal=Nature Microbiology |language=en |volume=2 |issue=4 |article-number=16270 |doi=10.1038/nmicrobiol.2016.270 |pmid=28134918 |issn=2058-5276|url-access=subscription }}</ref> When contaminated feces enter new ecosystems, their microbial population fosters horizontal gene transfer, dispersing ARGs to native microbes.<ref name=":1" /><ref>{{Cite journal |last1=von Wintersdorff |first1=Christian J. H. |last2=Penders |first2=John |last3=van Niekerk |first3=Julius M. |last4=Mills |first4=Nathan D. |last5=Majumder |first5=Snehali |last6=van Alphen |first6=Lieke B. |last7=Savelkoul |first7=Paul H. M. |last8=Wolffs |first8=Petra F. G. |date=2016 |title=Dissemination of Antimicrobial Resistance in Microbial Ecosystems through Horizontal Gene Transfer |journal=Frontiers in Microbiology |volume=7 |page=173 |doi=10.3389/fmicb.2016.00173 |doi-access=free |issn=1664-302X |pmc=4759269 |pmid=26925045}}</ref><ref>{{Cite journal |last1=Forsberg |first1=Kevin J. |last2=Reyes |first2=Alejandro |last3=Wang |first3=Bin |last4=Selleck |first4=Elizabeth M. |last5=Sommer |first5=Morten O. A. |last6=Dantas |first6=Gautam |date=2012 |title=The Shared Antibiotic Resistome of Soil Bacteria and Human Pathogens |journal=Science |language=en |volume=337 |issue=6098 |pages=1107–1111 |doi=10.1126/science.1220761 |issn=0036-8075 |pmc=4070369 |pmid=22936781 |bibcode=2012Sci...337.1107F }}</ref> ARGs remain in the soil resistome longer with manure use.<ref name=":0" /> Moreover, these genes persist chronically in the environment through co-resistance to metals, where these long-lasting metals continue to act as a selective pressure to maintain resistance.<ref>{{Cite journal |last1=Baker-Austin |first1=Craig |last2=Wright |first2=Meredith S. |last3=Stepanauskas |first3=Ramunas |last4=McArthur |first4=J.V. |date=2006 |title=Co-selection of antibiotic and metal resistance |url=https://linkinghub.elsevier.com/retrieve/pii/S0966842X06000515 |journal=Trends in Microbiology |language=en |volume=14 |issue=4 |pages=176–182 |doi=10.1016/j.tim.2006.02.006 |pmid=16537105 |url-access=subscription }}</ref><ref>{{Cite journal |last1=Liu |first1=Jinxin |last2=Taft |first2=Diana H. |last3=Maldonado-Gomez |first3=Maria X. |last4=Johnson |first4=Daisy |last5=Treiber |first5=Michelle L. |last6=Lemay |first6=Danielle G. |last7=DePeters |first7=Edward J. |last8=Mills |first8=David A. |date=2019 |title=The fecal resistome of dairy cattle is associated with diet during nursing |journal=Nature Communications |language=en |volume=10 |issue=1 |pages=4406 |doi=10.1038/s41467-019-12111-x |issn=2041-1723 |pmc=6765000 |pmid=31562300 |bibcode=2019NatCo..10.4406L }}</ref> Even without antibiotic contamination, fecal matter alters soil composition, fueling the growth of pre-existing resistant bacteria.<ref>{{Cite journal |last1=Udikovic-Kolic |first1=Nikolina |last2=Wichmann |first2=Fabienne |last3=Broderick |first3=Nichole A. |last4=Handelsman |first4=Jo |date=2014 |title=Bloom of resident antibiotic-resistant bacteria in soil following manure fertilization |journal=Proceedings of the National Academy of Sciences |volume=111 |issue=42 |pages=15202–15207 |doi=10.1073/pnas.1409836111 |doi-access=free |pmc=4210343 |pmid=25288759 |bibcode=2014PNAS..11115202U }}</ref>

==Human feces== {{main|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 called constipation.

The appearance of human fecal matter varies according to diet and health.<ref name="Stromberg2015">{{Cite web |title=Everybody poops. But here are 9 surprising facts about feces you may not know. |last=Stromberg |first=Joseph |work=Vox |date=22 January 2015 |access-date=3 December 2019 |url=https://www.vox.com/2015/1/22/7871579/poop-feces |archive-date=17 November 2019 |archive-url=https://web.archive.org/web/20191117130338/https://www.vox.com/2015/1/22/7871579/poop-feces |url-status=live}}</ref> 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.<ref name=tortora1 /><ref name=ciba />

After the meconium, the first stool expelled, a newborn's feces contains only bile, which gives it a dark 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.<ref name=ciba />

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.

== Fecal Microbiome and Disease == Feces plays a key role in representing the microbiome within the gut.<ref>{{Cite journal |last1=Zierer |first1=Jonas |last2=Jackson |first2=Matthew A. |last3=Kastenmüller |first3=Gabi |last4=Mangino |first4=Massimo |last5=Long |first5=Tao |last6=Telenti |first6=Amalio |last7=Mohney |first7=Robert P. |last8=Small |first8=Kerrin S. |last9=Bell |first9=Jordana T. |last10=Steves |first10=Claire J. |last11=Valdes |first11=Ana M. |last12=Spector |first12=Tim D. |last13=Menni |first13=Cristina |date=June 2018 |title=The fecal metabolome as a functional readout of the gut microbiome |journal=Nature Genetics |language=en |volume=50 |issue=6 |pages=790–795 |doi=10.1038/s41588-018-0135-7 |pmid=29808030 |pmc=6104805 |bibcode=2018NaGen..50..790Z |issn=1546-1718}}</ref><ref>{{Cite journal |last1=Marcobal |first1=A |last2=Kashyap |first2=P C |last3=Nelson |first3=T A |last4=Aronov |first4=P A |last5=Donia |first5=M S |last6=Spormann |first6=A |last7=Fischbach |first7=M A |last8=Sonnenburg |first8=J L |date=2013-10-01 |title=A metabolomic view of how the human gut microbiota impacts the host metabolome using humanized and gnotobiotic mice |journal=The ISME Journal |language=en |volume=7 |issue=10 |pages=1933–1943 |doi=10.1038/ismej.2013.89 |issn=1751-7362 |pmc=3965317 |pmid=23739052 |bibcode=2013ISMEJ...7.1933M }}</ref> The gut microbiome is a very important indicator and mediator of the health of the organism in which it resides.<ref>{{Cite journal |last1=O'Hara |first1=Ann M. |last2=Shanahan |first2=Fergus |date=2006-07-01 |title=The gut flora as a forgotten organ |url=https://doi.org/10.1038/sj.embor.7400731 |journal=The EMBO Reports |language=en |volume=7 |issue=7 |pages=688–693 |doi=10.1038/sj.embor.7400731 |issn=1469-3178 |pmc=1500832 |pmid=16819463}}</ref> The microbiome has function in the homeostasis, breakdown of foods otherwise not able to be digested. Within this gut microbiome the bacteria play an important role in the breakdown of foods, this often comes in the form of cell walls that are not broken down by standard processes of the organism but rather by the microbes that reside within the gut. These microbes also show presence in the feces of the animal that processed this food. <ref>{{Cite journal |last1=O'Hara |first1=Ann M. |last2=Shanahan |first2=Fergus |date=2006-07-01 |title=The gut flora as a forgotten organ |url=https://doi.org/10.1038/sj.embor.7400731 |journal=The EMBO Reports |language=en |volume=7 |issue=7 |pages=688–693 |doi=10.1038/sj.embor.7400731 |issn=1469-3178 |pmc=1500832 |pmid=16819463}}</ref><ref>{{Cite journal |last1=Heintz-Buschart |first1=Anna |last2=Wilmes |first2=Paul |date=2018-07-01 |title=Human Gut Microbiome: Function Matters |url=https://www.cell.com/trends/microbiology/abstract/S0966-842X(17)30251-2 |journal=Trends in Microbiology |language=English |volume=26 |issue=7 |pages=563–574 |doi=10.1016/j.tim.2017.11.002 |issn=0966-842X |pmid=29173869 |bibcode=2018TrMic..26..563H }}</ref><ref>{{Cite journal |last1=Karasov |first1=William H. |last2=Rio |first2=Carlos Martínez del |last3=Caviedes-Vidal |first3=Enrique |date=2011-03-17 |title=Ecological Physiology of Diet and Digestive Systems |url=https://www.annualreviews.org/content/journals/10.1146/annurev-physiol-012110-142152 |journal=Annual Review of Physiology |language=en |volume=73 |issue=73 |pages=69–93 |doi=10.1146/annurev-physiol-012110-142152 |pmid=21314432 |hdl=11336/14704 |issn=0066-4278|hdl-access=free }}</ref> The microbiome also contributes to immune responses in many ways such as competition with invasive bacteria, as well as improvement of the immune system.<ref>{{Cite journal |last1=Kamada |first1=Nobuhiko |last2=Seo |first2=Sang-Uk |last3=Chen |first3=Grace Y. |last4=Núñez |first4=Gabriel |date=May 2013 |title=Role of the gut microbiota in immunity and inflammatory disease |url=https://www.nature.com/articles/nri3430 |journal=Nature Reviews Immunology |language=en |volume=13 |issue=5 |pages=321–335 |doi=10.1038/nri3430 |pmid=23618829 |issn=1474-1741|url-access=subscription }}</ref>

The way that these bacteria are identified from the fecal samples is through 16s Ribosomal RNA sequencing or shotgun sequencing (genome of all microorganisms), which identifies the sequences of the microbiome and can be references to libraries for identification.<ref>{{Cite journal |last1=Jovel |first1=Juan |last2=Patterson |first2=Jordan |last3=Wang |first3=Weiwei |last4=Hotte |first4=Naomi |last5=O'Keefe |first5=Sandra |last6=Mitchel |first6=Troy |last7=Perry |first7=Troy |last8=Kao |first8=Dina |last9=Mason |first9=Andrew L. |last10=Madsen |first10=Karen L. |last11=Wong |first11=Gane K.-S. |date=2016-04-20 |title=Characterization of the Gut Microbiome Using 16S or Shotgun Metagenomics |journal=Frontiers in Microbiology |language=English |volume=7 |page=459 |doi=10.3389/fmicb.2016.00459 |doi-access=free |pmid=27148170 |pmc=4837688 |bibcode=2016FrMic...700459J |issn=1664-302X}}</ref><ref>{{Cite journal |last1=Janda |first1=J. Michael |last2=Abbott |first2=Sharon L. |date=September 2007 |title=16S rRNA Gene Sequencing for Bacterial Identification in the Diagnostic Laboratory: Pluses, Perils, and Pitfalls |journal=Journal of Clinical Microbiology |volume=45 |issue=9 |pages=2761–2764 |doi=10.1128/jcm.01228-07 |pmid=17626177 |pmc=2045242 }}</ref> Shotgun sequencing taxes the advantage when looking at the microbiome as a whole and trying to find changes within the taxa that are not as abundant, while 16s is beneficial to hone in and detect a specific part of the microbiome thus needing less material.<ref>{{Cite journal |last=Durazzi |first=Francesco |last2=Sala |first2=Claudia |last3=Castellani |first3=Gastone |last4=Manfreda |first4=Gerardo |last5=Remondini |first5=Daniel |last6=De Cesare |first6=Alessandra |date=2021-02-04 |title=Comparison between 16S rRNA and shotgun sequencing data for the taxonomic characterization of the gut microbiota |url=https://www.nature.com/articles/s41598-021-82726-y |journal=Scientific Reports |language=en |volume=11 |issue=1 |pages=3030 |doi=10.1038/s41598-021-82726-y |issn=2045-2322|pmc=7862389 }}</ref>

Feces is also a very strong indicator to disease, whether looking at just the physical properties or looking at the microbial composition of the fecal samples. Fecal biomarkers are something that is in the feces which can indicate the presence of certain diseases such as Inflammatory Bowel Disease.<ref>{{Cite journal |last1=Sutherland |first1=Andrew D. |last2=Gearry |first2=Richard B. |last3=Frizelle |first3=Frank A. |date=August 2008 |title=Review of Fecal Biomarkers in Inflammatory Bowel Disease |url=https://journals.lww.com/00003453-200851080-00017 |journal=Diseases of the Colon & Rectum |language=en |volume=51 |issue=8 |pages=1283–1291 |doi=10.1007/s10350-008-9310-8 |pmid=18543035 |issn=0012-3706|url-access=subscription }}</ref> There can also be disease indication from looking at the physical properties of the feces, such as if the feces is more loose in the form of diarrhea.<ref>{{Cite web |last=PMC |first=Europe |title=Europe PMC |url=https://europepmc.org/article/nbk/nbk361905 |access-date=2026-04-28 |website=europepmc.org |language=en}}</ref>

== Uses of animal feces == {{See also|Reuse of excreta|Human feces#Uses}}

===Fertilizer=== The feces of animals, e.g. guano and manure, often are used as fertilizer.<ref>{{Ullmann|doi=10.1002/14356007.n10_n01|title=Fertilizers, 2. Types|year=2009|last1=Dittmar|first1=Heinrich|last2=Drach|first2=Manfred|last3=Vosskamp|first3=Ralf|last4=Trenkel|first4=Martin E.|last5=Gutser|first5=Reinhold|last6=Steffens|first6=Günter|isbn=978-3527306732}}</ref>

===Energy === {{Further|Dry animal dung fuel}} Dry animal dung, such as that of camel, bison and cattle, is burned as fuel in many countries.<ref>{{Cite web |url=http://stcwa.org.au/ |title=STCWA |access-date=16 March 2021 |archive-date=13 March 2021 |archive-url=https://web.archive.org/web/20210313065242/http://stcwa.org.au/ |url-status=live}}</ref>

Animals such as the giant panda<ref name="Handwerk2013">{{Cite web |title=Panda Poop Might Help Turn Plants Into Fuel |last=Handwerk |first=Brian |work=National Geographic |date=11 September 2013 |access-date=3 December 2019 |url=https://www.nationalgeographic.com/news/energy/2013/09/130910-panda-poop-might-help-turn-plants-into-fuel/ |archive-date=3 December 2019 |archive-url=https://web.archive.org/web/20191203070716/https://www.nationalgeographic.com/news/energy/2013/09/130910-panda-poop-might-help-turn-plants-into-fuel/ }}</ref> and zebra<ref name="Ray2011">{{Cite web |title=Cars Could Run on Recycled Newspaper, Tulane Scientists Say |last=Ray |first=Kathryn Hobgood |work=Tulane News |date=25 August 2011 |access-date=3 December 2019 |url=https://news.tulane.edu/pr/cars-could-run-recycled-newspaper-tulane-scientists-say |archive-date=4 March 2022 |archive-url=https://web.archive.org/web/20220304214914/https://news.tulane.edu/pr/cars-could-run-recycled-newspaper-tulane-scientists-say |url-status=live}}</ref> possess gut bacteria capable of producing biofuel. The bacterium in question, Brocadia anammoxidans, can be used to synthesize the rocket fuel hydrazine.<ref name="Handwerk2005">{{Cite web |title=Bacteria Eat Human Sewage, Produce Rocket Fuel |last=Handwerk |first=Brian |work=National Geographic News |via=wildsingapore.com |date=9 November 2005 |access-date=3 December 2019 |url=http://www.wildsingapore.com/news/20051112/051109-5.htm |archive-date=13 March 2020 |archive-url=https://web.archive.org/web/20200313110748/http://www.wildsingapore.com/news/20051112/051109-5.htm |url-status=live}}</ref><ref>{{cite journal |pmc=3264106 |pmid=22138989 |doi=10.1128/AEM.07113-11 |volume=78 |issue=3 |title=Hydrazine synthase, a unique phylomarker with which to study the presence and biodiversity of anammox bacteria |year=2012 |journal=Appl. Environ. Microbiol. |pages=752–8 |last1=Harhangi |first1=HR |last2=Le Roy |first2=M |last3=van Alen |first3=T |last4=Hu |first4=BL |last5=Groen |first5=J |last6=Kartal |first6=B |last7=Tringe |first7=SG |last8=Quan |first8=ZX |last9=Jetten |first9=MS |last10=Op |last11=den Camp |first11=HJ |bibcode=2012ApEnM..78..752H}}</ref>

=== Coprolites and paleofeces ===

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.<ref>{{Cite web |url=https://www.dictionary.com/browse/coprolite |title=Definition of coprolite | Dictionary.com |website=dictionary.com |access-date=16 March 2021 |archive-date=9 November 2020 |archive-url=https://web.archive.org/web/20201109120934/https://www.dictionary.com/browse/coprolite |url-status=live}}</ref> 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.<ref>{{cite journal |last1=Poinar |first1=Hendrik N. |display-authors=etal |date=10 April 2001 |title=A Molecular Analysis of Dietary Diversity for Three Archaic Native Americans |journal=PNAS |volume=98 |issue=8 |pages=4317–4322 |doi=10.1073/pnas.061014798 |pmc=31832 |pmid=11296282 |bibcode=2001PNAS...98.4317P |doi-access=free}}</ref> 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.<ref name="Feder2008">{{cite book |last=Feder |first=Kenneth L. |title=Linking to the Past: A Brief Introduction to Archaeology |url=https://books.google.com/books?id=XEFsPwAACAAJ |year=2008 |publisher=Oxford University Press |isbn=978-0-19-533117-2 |access-date=3 December 2019 |archive-date=1 August 2020 |archive-url=https://web.archive.org/web/20200801124206/https://books.google.com/books?id=XEFsPwAACAAJ |url-status=live}}</ref>

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.<ref>{{cite journal |last=Stokstad |first=Erik |date=28 July 2000 |title=Divining Diet and Disease From DNA |journal=Science |volume=289 |issue=5479 |pages=530–531 |doi=10.1126/science.289.5479.530 |pmid=10939960 |s2cid=83373644}}</ref>

===Other uses=== [[File:Pet Waste Station.jpg|thumb|A pet waste station in Tucker, Georgia, US]] Animal dung occasionally is used as a cement to make adobe (mudbrick) huts,<ref>{{cite web |url=http://www.greenhouse.gov.au/yourhome/technical/fs34d.htm |title=Your Home Technical Manual – 3.4d Construction Systems – Mud Brick (Adobe) |access-date=9 July 2007 |archive-url=https://web.archive.org/web/20070706132354/http://www.greenhouse.gov.au/yourhome/technical/fs34d.htm  |archive-date=6 July 2007}}</ref> or even in throwing sports, especially with cow and camel dung.<ref>{{cite web |url=http://www.abc.net.au/news/newsitems/200307/s900527.htm |title=Dung Throwing contests |website=Australian Broadcasting Corporation |archive-url=https://web.archive.org/web/20071011200318/http://abc.net.au/news/newsitems/200307/s900527.htm |archive-date=11 October 2007}}</ref>

Kopi luwak, or civet coffee, is coffee made from coffee beans that have been eaten and excreted by Asian palm civets (''Paradoxurus hermaphroditus'').<ref>{{cite journal |last=Marcone |first=M. |title=Composition and properties of Indonesian palm civet coffee (Kopi Luwak) and Ethiopian civet coffee |year=2004 |journal=Food Research International |volume=37 |issue=9 |pages=901–912 |doi=10.1016/j.foodres.2004.05.008 |bibcode=2004FdRI...37..901M |url=https://nature.berkeley.edu/garbelottoat/wp-content/uploads/marcone-2004.pdf}}</ref>

Giant pandas provide fertilizer for the world's most expensive green tea.<ref name="huffpo"/> 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.<ref name="huffpo">{{cite news |author=Topper, R |date=15 October 2012 |title=Elephant Dung Coffee: World's Most Expensive Brew Is Made With Pooped-Out Beans |newspaper=HuffPost |access-date=10 December 2012 |url=http://www.huffingtonpost.com/2012/10/15/elephant-dung-coffee-black-ivory_n_1968096.html |archive-date=3 September 2017 |archive-url=https://web.archive.org/web/20170903050156/http://www.huffingtonpost.com/2012/10/15/elephant-dung-coffee-black-ivory_n_1968096.html |url-status=live}}</ref> 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",<ref>{{OED|pure|id=154843}} n., 6</ref> 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.<ref>{{cite web |url=http://www.rohmhaas.com/history/ourstory/innovation_leatherbreakthrough.htm |title=Rohm and Haas Innovation - The Leather Breakthrough |publisher=Rohmhaas.com |date=1 September 1909 |access-date=27 October 2012 |archive-url=https://web.archive.org/web/20121019175930/http://www.rohmhaas.com/history/ourstory/innovation_leatherbreakthrough.htm |archive-date=19 October 2012}}</ref> Dog feces collectors were known as ''pure finders''.<ref>{{Cite book |last=Johnson |first=Steven |title=The ghost map: the story of London's most terrifying epidemic--and how it changed science, cities, and the modern world |date=2006 |publisher=Riverhead Books |isbn=1-59448-925-4 |location=New York |oclc=70483471 }}</ref>

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.<ref>{{cite news |url=https://www.thehindu.com/news/national/cow-urine-can-cure-cancer-bjp-member-in-rs/article7012010.ece |title=Cow dung, urine can cure cancer: BJP MP |date=19 March 2015 |access-date=17 September 2019 |last=Ramachandran |first=Smriti Kak |newspaper=The Hindu |archive-date=1 October 2019 |archive-url=https://web.archive.org/web/20191001081243/https://www.thehindu.com/news/national/cow-urine-can-cure-cancer-bjp-member-in-rs/article7012010.ece |url-status=live}}</ref>

== Terminology == [[File:Cyclosia papilionaris by Kadavoor.JPG|thumb|''Cyclosia papilionaris'' consuming bird droppings]]

''Feces'' is the scientific terminology, while the term ''stool'' is also commonly used in medical contexts.<ref>{{cite web |url=http://medical-dictionary.thefreedictionary.com/stool |title=stool |via=The Free Dictionary |access-date=18 April 2017 |archive-date=11 March 2019 |archive-url=https://web.archive.org/web/20190311062946/http://medical-dictionary.thefreedictionary.com/stool |url-status=live}}</ref> Outside of scientific contexts, these terms are less common, with the most common layman's term being ''poo'' or ''poop''. The terms ''shit and crap are'' also in common use, although these are widely considered vulgar or offensive. There are many other terms, see below.

=== Etymology === 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;<ref>{{cite web |url=http://www.medterms.com/script/main/art.asp?articlekey=3400 |title=Feces definition – Medical Dictionary definitions of popular medical terms easily defined on MedTerms |work=Medterms |publisher=Medterms.com |date=19 March 2012 |access-date=11 November 2013 |archive-date=11 November 2013 |archive-url=https://web.archive.org/web/20131111175053/http://www.medterms.com/script/main/art.asp?articlekey=3400 |url-status=live}}</ref> out of various major dictionaries, only one enters variation from plural agreement.<ref name="AHD">{{Citation |author=Houghton Mifflin Harcourt |title=The American Heritage Dictionary of the English Language |publisher=Houghton Mifflin Harcourt |url=https://ahdictionary.com/ |postscript=. |access-date=17 March 2015 |archive-date=25 September 2015 |archive-url=https://web.archive.org/web/20150925104737/https://ahdictionary.com/ |url-status=live}}</ref>

===Synonyms=== {{Further|Shit}} "Feces" is used more in biology and medicine than in other fields (reflecting science's tradition of classical Latin and Neo-Latin) *In hunting and tracking, terms such as ''dung'', ''scat'', ''spoor'', and ''droppings'' normally are used to refer to non-human animal feces *In husbandry and farming, ''manure'' is common. *''Stool'' is a common term in reference to human feces. For example, in medicine, to diagnose the presence or absence of a medical condition, a stool sample sometimes is requested for testing purposes.<ref>{{cite web |author=Steven Dowshen, MD |url=http://kidshealth.org/parent/system/medical/test_bac_culture.html |title=Stool Test: Bacteria Culture |publisher=Kidshealth |date=September 2011 |access-date=11 February 2012 |archive-date=19 February 2012 |archive-url=https://web.archive.org/web/20120219213101/http://kidshealth.org/parent/system/medical/test_bac_culture.html |url-status=live}}</ref> *The term ''bowel movement(s)'' (with each movement a defecation event) is also common in health care.

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) or to crude humor (such as ''crap'', ''dump'', ''load'' and ''turd'').

[[File:Badaia - Heces de caballo 02.jpg|thumb|Horse dung]]

=== 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 * 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 (before motor vehicles became common, horse droppings were a big part of the rubbish communities needed to clean off roads)

===Feelings of disgust=== {{Main|Human feces#Disgust and shame}}

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.<ref>{{cite journal |last1=Moore |first1=Alison M. |title=Coprophagy in nineteenth-century psychiatry |journal=Microbial Ecology in Health and Disease |date=8 November 2018 |volume=30 |issue=sup1 |article-number=1535737 |doi=10.1080/16512235.2018.1535737 |pmid=30425610 |pmc=6225515}}</ref> Disgust toward feces appears to be strongest in cultures where flush toilets make olfactory contact with human feces minimal.<ref>{{Cite web |url=https://www.upworthy.com/yes-poop-is-gross-but-thats-not-the-only-reason-for-its-shameful-social-stigma |title=Yes, poop is gross. But that's not the only reason for its shameful social stigma. |date=25 May 2016 |website=Upworthy |access-date=8 April 2020 |archive-date=31 July 2020 |archive-url=https://web.archive.org/web/20200731052613/https://www.upworthy.com/yes-poop-is-gross-but-thats-not-the-only-reason-for-its-shameful-social-stigma |url-status=live}}</ref><ref>{{Cite web |url=https://www.bbc.com/future/article/20131111-hate-poo-theres-good-reason-why |title=Why do humans hate poo so much? |first=Jason G. |last=Goldman |date=11 November 2013 |publisher=BBC |access-date=8 April 2020 |archive-date=31 March 2019 |archive-url=https://web.archive.org/web/20190331004423/http://www.bbc.com/future/story/20131111-hate-poo-theres-good-reason-why |url-status=live}}</ref> 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 a Pile of Poo emoji represented in Unicode as {{unichar|1F4A9|pile of poo}}, called ''{{vanchor|unchi}}'' or ''unchi-kun'' in Japan.<ref>{{citation |title=The Oral History Of The Poop Emoji (Or, How Google Brought Poop To America) |date=18 November 2014 |url=https://www.fastcompany.com/3037803/the-oral-history-of-the-poop-emoji-or-how-google-brought-poop-to-america |work=Fast Company |access-date=9 November 2016 |archive-date=3 April 2018 |archive-url=https://web.archive.org/web/20180403070613/https://www.fastcompany.com/3037803/the-oral-history-of-the-poop-emoji-or-how-google-brought-poop-to-america |url-status=live |last1=Schwartzberg |first1=Lauren }}</ref><ref>{{citation |title=America Needs its own Emojis |date=7 March 2015 |url=https://www.nytimes.com/2015/03/08/opinion/sunday/turn-emojis-red-white-and-blue.html |first=Damon |last=Darlin |newspaper=The New York Times |access-date=1 March 2017 |archive-date=30 October 2016 |archive-url=https://web.archive.org/web/20161030180735/http://www.nytimes.com/2015/03/08/opinion/sunday/turn-emojis-red-white-and-blue.html |url-status=live}}</ref> ===Jokes === Poop is the center of toilet humor, and is commonly an interest of young children and teenagers.<ref>{{Cite book |last=Praeger |first=Dave |title=Poop Culture: How America Is Shaped by Its Grossest National Product |publisher=Feral House |year=2007 |isbn=978-1-932595-21-5 |location=United States |language=English}}</ref>

== See also == {{Portal|Biology}} {{colbegin}} * Coprophagia * Coprophilia * Coprophilous fungi * Cow dung * Dung paper * Excretory system * Fecal microbiota * Fecal plug * Jenkem * Manure * Metabolic waste * Night soil * Sanitation * Scatology * Whale feces * Zooplankton fecal pellets {{colend}}

==References== {{Reflist}}

==External links== {{Wiktionary|feces|faeces}} {{Commons}} {{Scholia|topic}} * [http://www.medfriendly.com/feces.html Article on Feces] – MedFriendly

Category:Feces Category:Animal physiology