Curious children: why do people have diarrhoea? | Kiowa County Press

Whatever its cause, diarrhea is uncomfortable. Rapeepong Puttakumwong/Moment via Getty Images

Hannibal Person, University of Washington

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Why do people have diarrhoea? – AAA, 10, Philadelphia


The digestive system breaks down everything you eat and drink to absorb nutrients and produce the energy your body needs. Whatever solids cannot be broken down and used, get excreted as poo.

Poop comes in many shapes, sizes, colors, and consistencies.

doctors like me that treat people with digestive problems use what is called the Scale stool Bristol to assess the texture of the poo. It ranges from Type 1 – separate hard chunks – to Type 7 – liquid with no solid chunks. The texture of the best poops, Type 4, resembles a mushy banana.

When your the poo is loose and runny and goes out like this at least three times a day, you have diarrhea. This can be uncomfortable and inconvenient, as diarrhea tends to come out quickly and without warning.

Illustration of the seven categories of poo, ranging from too firm to watery.
The Bristol Stool Scale classifies poo into seven categories ranging from hard pellets from constipation to smeared liquid from diarrhea. VectorMine/iStock via Getty Images Plus

Watch out for bad germs

As food exits the stomach, liquid travels through the small intestine, where nutrients are absorbed. The remains flow into the large intestine, where the water is absorbed and the poop is formed.

When the small intestine or the large intestine cannot do its job, the poop will be watery.

Diarrhea usually occurs due to infections caused by many viruses, bacteria and parasites.

This is why there is rules for keeping drinking water clean and food safety. This is also why you should wash your hands before eating.

These germs cause diarrhea in different ways. Often they irritate the intestines, interfering with water absorption. Some germs cause diarrhea by releasing chemicals which cause the intestines to release fluid, making the poop even more watery. When these germs come from foodsymptoms may include vomiting, abdominal pain, and diarrhea.

Of course, not all microbes are bad.

In fact, your digestive system is filled with billions of bacteria and other germs that help you digest food and protect you from bad germs. Taking antibiotics for an infection can cause diarrhea killing those good bacteria as well as the ones that made you sick in the first place. But people are generally better once they finish the prescribed antibiotics and the good bacteria have a chance to recover.

People with diarrhea need to consume plenty of fluids to stay hydrated. Water is the best. To avoid juice and a soda, which can make diarrhea worse. Also avoid foods that can make your digestive system work harder, such as dairy products.

Eat sweet potatoes, oats, beets and other fiber-rich foods can help firm up loose poop. Never take any medicine, even if it doesn’t require a prescription, for diarrhea without first talking to a doctor.

Many other causes

There are many other causes of diarrhea.

Some people are born with or develop conditions during their lifetime that can cause diarrhea.

A common example is Lactose intolerance. Lactose is a sugar found in milk that requires special enzyme, called lactase, to digest it in the small intestine. There are people who have little or even none of this enzyme in their small intestine. As a result, the lactose moves through their large intestine without being broken down or absorbed, leaving the poo very runny.

Celiac disease can also trigger diarrhea. People with it have difficulty digesting gluten, a protein found in wheat and other grains. For people with celiac disease, eating gluten can damage the small intestine by activating their own immune system. This damage is reversible with a gluten-free diet, but the diarrhea may linger until the small intestine heals and can do its job.

Others have digestive system allergy. They should avoid eating specific foods to prevent diarrhea and other symptoms.

Some medications make you poop more often.

There are also medical conditions, like inflammatory bowel diseaselike Crohn’s disease and ulcerative colitisin which the small intestine, large intestine, or both become inflamed over time.

Even your brain can play a role: experiencing anxiety or become stressed can cause loose poop. Certain conditions, such as irritable bowel syndromewhere the brain and intestines do not communicate well with each other, can lead to abdominal pain and diarrhea, especially under stress.

Certain cancers and certain tumors can also cause diarrhea.

Finally, for some people, eating spicy or fatty foods or consuming artificial sweeteners or large amounts of caffeine can cause diarrhoea.

Even if you find it disgusting, I recommend that you be careful with your poo. If you have diarrhea all the time, rather than occasionally, you may need to see a doctor.


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The conversation

Hannibal PersonAssistant Professor of Gastroenterology and Hepatology, Faculty of Medicine, University of Washington

This article is republished from The conversation under Creative Commons license. Read it original article.

About Florence M. Sorensen

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