Feces

Feces (also called faeces or fæces) are the solid or semi-solid parts of food that our bodies cannot digest. They are made in the large intestine where special tiny living things called bacteria help break down the food. Feces contain a small amount of waste products and dead cells from our gut.

Feces leave our bodies through a part called the anus or, in some animals, through a structure called the cloaca, during a process known as defecation.

Feces are important for the environment. They can be used as fertilizer or soil conditioner to help plants grow. In some places, dried feces are burned for fuel or used in construction. Scientists have also found ways to use human feces for medicine, such as in fecal transplants, which help people who are very sick with bad gut bacteria. Together, urine and feces are called excreta.

Characteristics

Feces have a special smell because of things like skatole, sulfur compounds, amines, and carboxylic acids. Skatole comes from a substance in food called tryptophan.

Our bodies get rid of feces to keep us healthy. This happens through a process called defecation, where the body uses muscles and gases to push the feces out through the anus or cloaca.

Ecology

After an animal eats food, what is left over comes out as waste. Even though this waste has less energy than the food, it can still hold a lot of energy—sometimes about half of what was in the original food. This leftover energy helps other small plants and animals in nature.

Many tiny living things and insects, like dung beetles, eat this waste. Some animals also eat waste to get extra nutrients. For example, baby elephants sometimes eat their mothers' waste to help their own tummies work better.

Waste can also help plants grow. When animals eat fruit, they may pass seeds through their waste. This helps the seeds spread far away from the plant, giving them a better chance to grow.

Environmental impacts

Fecal resistome

The "fecal resistome" is the collection of genes in human and animal waste that can make germs stronger against medicines. When people and animals take medicines, these genes can end up in the environment through waste and water. This can happen when waste is used on farms or when it goes into water systems. These genes can then spread to other germs in the soil, making it harder to treat infections. Even without medicines, waste can change the soil and help germs that are already strong to grow more.

Human feces

Main article: Human feces

People eliminate solid or semi-solid waste from their bodies several times a day, every day, or once every few days. When this waste becomes very hard and disrupts the normal routine for several days, it is called constipation.

The look of this waste changes based on what a person eats and their health. Usually, it is soft and has a layer of mucus. A mix of bile and bilirubin from dead red blood cells gives it its typical brown color.

Newborn babies first pass a special waste called meconium, which is different. After that, a baby’s waste is dark yellow-green because it contains only bile. Babies who are breast feeding have soft, pale yellow waste that doesn’t smell much. Once babies start eating other foods and their bodies begin to release bilirubin from dead red blood cells, their waste turns the familiar brown color.

As people grow, their waste can change color and texture. If waste moves quickly through the intestines, it may look greenish. If there is no bilirubin, the waste may look clay-like.

Fecal Microbiome and Disease

Feces show what’s living inside our gut, which helps keep us healthy. These tiny living things help break down food we can’t digest on our own and support our immune system.

Scientists can study these tiny living things by looking at special parts of their DNA from fecal samples. This helps them learn about changes in our gut and can show if someone might have a health problem, like a condition that makes the gut inflamed. The way feces look or feel, such as being loose, can also give clues about health.

Uses of animal feces

See also: Reuse of excreta and Human feces § Uses

Animal waste, such as guano and manure, is often used to help plants grow. It works like fertilizer to give soil nutrients.

Dry animal waste, like that from camel, bison, and cattle, can be burned for fuel in many places. Some animals, like the giant panda and zebra, have special bacteria in their stomachs that can help make energy sources.

Fossilized waste, called a coprolite, helps scientists learn about animals that lived long ago. Ancient waste found in places like caves can tell us about what people ate and their health by studying seeds, tiny bones, and other bits inside. This waste stays preserved because of natural processes.

Animal waste also has other uses. It can be used to build simple houses, make special kinds of coffee, and even create paper. Some animals need to eat their mothers' waste to help them digest plants.

Terminology

Feces is the scientific word for what comes out of our bodies when we go to the bathroom. Many people also call this stool, poo, or poop. Other words like shit and crap are used too, but they can be rude or offensive.

There are many different words to describe feces, especially for animals. For example, cow poop is often called cow dung, and bird droppings are just called droppings. In farming, animal waste is usually called manure. Different animals have special names for their waste, like scat for wild carnivores or guano for seabirds and bats.

Society and culture

Feelings of disgust

Main article: Human feces § Disgust and shame

In every culture, people feel different levels of icky feelings about feces. Young children, usually under two years old, don’t feel this way, which shows it’s learned through culture. The feeling of ick is strongest in places where flush toilets keep smells away.

Social media

There is a Pile of Poo emoji in Unicode called unchi or unchi-kun in Japan.

Jokes

Poop is a big part of toilet humor and is something that young children and teenagers often find funny.