Diarrhea

Diarrhea, also called the runs or the trots, is when someone has three or more loose or watery bowel movements in one day. It usually lasts a few days and can make the body lose fluids. This can lead to dehydration. Early signs of dehydration include skin that doesn’t bounce back quickly and feeling irritable.

Most cases of diarrhea happen because of an infection in the intestines from a virus, bacterium, or parasite. These infections often come from eating bad food or drinking unsafe water, or from being close to someone who is sick. Diarrhea can also be caused by things like lactose intolerance, some medicines, or health conditions such as irritable bowel syndrome.

Diarrhea can be prevented by keeping things clean, such as improving sanitation, drinking clean water, and washing hands with soap. Giving babies breastfeeding for at least six months and vaccination against rotavirus also helps. The best treatment is an oral rehydration solution, which is clean water mixed with a little salt and sugar. Zinc tablets are also useful. In severe cases, medicines like intravenous fluids might be needed, but most people get better just by drinking fluids.

Diarrhea is most common in developing countries, where young children often get it. It can lead to problems like malnutrition and slow growth in children.

Terminology

The word diarrhea comes from Ancient Greek, meaning "flow through." In American English, we spell it diarrhea, while British English spells it diarrhoea. Canadian English can use either spelling.

People sometimes use fun names for this condition, like "the runs" or "the trots."

Definition

Diarrhea happens when someone has three or more loose or watery stools in one day, or more than what is normal for them.

Acute diarrhea is when this happens for less than 14 days. It can be watery and is sometimes called AWD (Acute Watery Diarrhoea). There are different types of diarrhea, such as secretory, osmotic, exudative, inflammatory, and dysentery.

Health effects

Diarrhea can affect a child's body and mind. It can make it hard for children to get the nutrition they need to grow strong. Even after treating other problems, children who have had severe diarrhea might not do as well on thinking and learning tests.

Diarrhea can also make the body lose important fluids and minerals. This can make a child feel very tired. It might also make medicines less effective because they move through the body too quickly. Because of these effects, diarrhea can make daily life harder, especially for older people who might need extra care.

Causes

In the later stages of digestion, our bodies add water and fluids to help break down food. The large intestine usually takes this water back in to keep us hydrated. But sometimes, it can't take in all the water, and we end up with loose or watery stools — that's diarrhea.

Acute diarrhea often happens because of a virus, especially in young children. For people traveling in new places, bacteria can be the main cause. Some toxins from foods and certain medicines can also lead to sudden diarrhea. Long-term diarrhea can be linked to health problems affecting the intestines, like inflammatory bowel disease or conditions that make it hard to absorb nutrients properly.

Pathophysiology

Evolution

Some scientists think that diarrhea might help the body fight off sickness. If you stop diarrhea too quickly, it might take longer to feel better. For example, a study from 1973 found that people with a certain infection who used medicine to stop their diarrhea stayed sick for much longer than those who did not use the medicine. These scientists believe that letting the body have diarrhea could be a natural part of getting well.

Diagnostic approach

Sometimes doctors need to do more tests to find out why someone has diarrhea. This is especially true for babies, young children with bad diarrhea, or if the diarrhea has blood in it, lasts more than two days, or comes with other symptoms like stomach pain, fever, or weight loss. Travelers and people who prepare food for others also might need extra checks, as they could spread the problem.

If diarrhea continues for over four weeks, doctors might suggest several tests. These can include checking blood for signs of anemia or thyroid problems, testing stool for certain germs or parasites, and in some cases, looking at the colon with a special camera. Some tests help find out if there are issues like lactose intolerance or problems with the intestines. Not all tests are needed for everyone—doctors decide based on what they think might be causing the problem.

Epidemiology

Diarrhea is a common health problem around the world. Many children, especially in places without clean water, can get very sick from it.

The World Health Organization has helped reduce deaths from diarrhea. Climate change can also affect how often diarrhea happens. Even animals, like primates, can sometimes get diarrhea.

Prevention

Further information: WASH § Health aspects

Improving drinking water and keeping things clean can help stop diarrhea. Using water filters, getting clean piped water, and having good sewer systems can all lower the chances of getting sick. Washing hands with soap, using toilets, and having proper sanitation also help keep diarrhea away.

Washing hands with soap and water can cut the risk of diarrhea. In places with less money, not everyone has easy access to soap and water, making it harder to stay healthy. Teaching people good hygiene habits can make a big difference.

Clean water is very important. Providing clean water and good sanitation can greatly reduce how often people get sick. Treating water with chlorine can also help keep it safe.

Vaccines can help prevent some diseases that cause diarrhea. Vaccines for rotavirus have helped save lives, especially in places where this virus is common.

Good nutrition matters. Giving zinc supplements has been shown to lower the chances of diarrhea. Vitamin A can also help. Breastfeeding helps protect babies from diarrhea.

Using probiotics can help prevent diarrhea in people taking antibiotics.

Management

Most diarrhea can be treated by replacing lost fluids and salts. This is usually done by drinking special solutions, like oral rehydration therapy, or in serious cases, through special medical ways like intravenously. It’s important for children with diarrhea to keep eating normally. Eating helps them get better faster and supports their growth.

Sometimes, medicines such as loperamide and bismuth subsalicylate can help, but they should only be used when a doctor says it’s safe.

Fluids

Oral rehydration solution (ORS) is a special mix of slightly sweetened and salty water that helps prevent dehydration. Simple home solutions like salted rice water or soups with salt can also work. Commercial solutions like Pedialyte are available, and groups like UNICEF provide packets of salts and sugar for making ORS at home.

It’s important to start giving fluids as soon as possible to prevent dehydration. If a child vomits, wait a few minutes and then give small amounts of the solution slowly. Drinks with a lot of sugar, like soft drinks, aren’t recommended for young children because they can make dehydration worse. Plain water can be used if special ORS isn’t available.

Eating

Children with diarrhea should keep eating normally. Stopping food can make diarrhea last longer. Breastfed babies should continue to breastfeed, and other children should eat their usual foods. Foods with certain fibers might help, but others could make things worse.

Medications

Main article: Antidiarrhoeal

Some medicines can help with diarrhea, but they should only be used in certain situations. Antibiotics are usually not needed unless a specific type of infection is causing the diarrhea. Some medicines can help reduce the number of bowel movements but might not shorten the illness. Natural substances like Diosmectite and other treatments can also help with symptoms.

Alternative therapies

Eating green bananas can help children with diarrhea recover faster. Taking zinc might help older children in areas where malnutrition is common. Some studies show that probiotics don’t greatly change how long diarrhea lasts, but they might help prevent diarrhea caused by antibiotics in adults. For children who can't digest lactose, special enzymes can help with symptoms when they drink dairy products.