Can You Get Diarrhea From Swimming? (How to Prevent One)


Nothing seems more inviting than the crystal-clear water of a swimming pool on a hot summer day. But if you’re an active member of any health-conscious group, you might have heard stories about people experiencing diarrhea, nausea, fever, etc., after swimming. So, can you get diarrhea from swimming for real?

Yes, you can get diarrhea while swimming if you somehow swallow contaminated water. Cryptosporidium is the parasitic genus responsible for diarrhea outbreaks, and 7,465 people became sick due to the outbreaks between 2009 and 2017.

Which Germs in Contaminated Water Cause Diarrhea?

Contaminated water in swimming pools, hot tubs, and water playgrounds contains not only one but several diarrhea-causing germs. Here are a few of them that can cause diarrhea and other major illnesses:


Commonly known as Crypto, Cryptosporidium is the parasite responsible for Cryptosporidiosis outbreaks that cause watery diarrhea. It’s the most common cause of swimming-related diarrhea outbreaks. The parasite is found in water, soil, food, or dirty hands contaminated with the feces of infected humans or animals.

There are a few reasons why Crypto is more widespread than other germs. First of all, the parasite has a tough protective shell that helps it survive pool chemicals and high chlorine levels for days. Secondly, swallowing a tiny amount of Crypto contaminated water is enough to give you weeks of watery diarrhea.


A single bowel movement of an infected shed up to 100,000,000 Crypto germs. And swallowing only 10 of them can give you severe Cryptosporidiosis. Lastly, Cryptosporidium shows excellent weather resistance, and the parasite is found in almost every region throughout the world.

More than 444 outbreaks caused by Cryptosporidium were reported by the Centers for Disease Control and Prevention (CDC) between 2009 and 2017. The results of these outbreaks are alarming, causing 7,465 cases of illnesses, 287 cases of hospitalizations, and one unfortunate death.


It’s a bacteria found in hot tubs, water parks, or pool water, causing Shigellosis, a condition that directly affects the digestive system. Symptoms of Shigellosis include diarrhea with blood and mucus, nausea, stomach pain, etc.

Unfortunately, Shigella is a highly contagious bacteria, and it spreads from the feces of an infected person. For example, if you change diapers that are contaminated and forget to wash your hand, the bacteria will go in the water with you and affect you and other swimmers.

This bacteria is particularly dangerous for children under five and people with weak immune systems. Thankfully, the symptoms don’t get very dangerous, and the affected person usually clears up within a week.



Although less common, Norovirus infection is more of a threat to swimmers than most germs. That’s because this virus is very contagious, and it can be caused not only by swallowing contaminated water but also by the close contact or touch of an infected person.

Young children, people with weakened immune systems, and old adults are mostly affected by Norovirus. The symptoms include watery diarrhea, nausea, muscle pain, and fever.

However, the symptoms usually last only 1 to 3 days, and the infected person can fully recover without any special treatment.

E. coli O157

Most strains of E. coli bacteria are harmless, and many of them naturally live in our intestines. But, strains like E. coli O157 can contaminate public pools, hot springs, and rivers, causing diarrheal illness, vomiting, and severe stomach cramps to swimmers.

Swallowing only a small amount of contaminated water will give you a week of watery or bloody diarrhea. Luckily, E. coli O157 can’t survive in Chlorinated water, and the risk factors related to this bacteria are also few.

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Video Creator: KOAT

How Germs Spread in Swimming Pools, Hot Tubs, and Other Sources

Swimming-related illness isn’t limited to diarrhea only. Hot tub rash, Pontiac fever, Swimmer’s ear, lung infection, Swimmer’s itch, etc., are also caused by various water-borne germs. Here are a few ways how germs and other toxins might spread in the water:

Swimming While Sick

You might think diarrhea isn’t contagious, and it’s fine if you swim when you’re sick. But that’s not true at all, and you might end up contaminating the water unknowingly. According to the researchers, a person contains 0.14g of fecal matter on their body surface at any given time. This can wash off the person’s body and pollute the water with harmful germs.

Swallowing Contaminated Water

Most diarrhea-causing germs can’t infect you upon touching the dirty water. They can only affect you once you swallow the dirty water.

Even the tiniest amount of water can contain many different germs causing severe diarrhea, vomiting, and stomach cramps.

Urine in Water

We all know peeing in a public pool, water park, or hot tub is unhygienic and gross. Urine contains various bacterial species that are naturally found in our bladders. If you’re suffering from a disease or urinal infection, the germs will come out of your body through the urine and end up contaminating the water.


Moreover, urine contains a number of waste products and chemical components that react with the chlorine in the pool water and create many harmful toxins.

Unmonitored Sources

You might have the urge to jump into an unmonitored lake on a nice summer day. But it’s not healthy at all as you might be sick with diarrhea, rash, itching, etc. Unmonitored rivers, lakes, and water streams are often contaminated by the waste of animals and various chemical factories.

Some unmonitored water sources are so polluted that you can get rashes just by touching them. Also, if the water gets inside your ear through your outer ear canal, it’ll cause the growth of fungus or bacteria, resulting in itching and pain.

How to Prevent Getting Diarrhea from Swimming

You should always follow a few safety measures if you don’t want to get diarrhea from swimming. Below we have rounded up some most effective preventive steps for avoiding swimming-related illnesses. Let’s have a look.

Swim in Clean Water

First things first, you have to make sure the water is clean and well-maintained before getting into swimming pools. Avoid swimming in unmonitored rivers, lakes, and public pools. If you own a swimming pool or hot tub, you need to make sure you’re maintaining the water quality and pH levels.


The best way of disinfecting your pool water is to use chlorine. It reacts with the water and creates a mild acid that’s capable of killing the most dangerous germs.

Remember, you need to be careful with the application as overuse of chlorine might cause allergies and rashes. The CDC recommended chlorine level for your swimming pool is only 1 ppm.

As for the pH level, it should be between 7.2 and 7.8 in ideal conditions. You can visit the nearest pool supply stores and get some test strips to check the pH level of your swimming pool and hot tub.

Maintain Personal Hygiene

You can’t expect swimming pools and water playgrounds to be completely germ-free. So, to avoid diarrhea and other water-borne diseases, it’s essential to maintain personal hygiene.

Try to take a shower before and after taking a dip in the public swimming pools. Rinsing off your skin can remove a large number of germs from your body. Don’t urinate in a public pool, and don’t get in when you’re sweaty. Always wash your hands before entering the water, especially if you have small children.


Most importantly, avoid swimming when you’re sick. If you have suffered from diarrhea, wait at least two weeks before getting to recreational water. Also, don’t hesitate to inform the pool staff about any fecal incidents.

Be Careful with Kids

Children and older adults are at most risk of being sick with diarrhea from swimming. So, you need to be particularly careful with them. Teach your child not to pee in the water. Also, show them the correct ways of swimming and tell them how to avoid swallowing water.

Schedule regular bathroom breaks for your kids. Instead of changing the diapers near the pool area, use a bathroom.

In addition to these safety measures, here are a few more things you should consider:

  • Don’t swim in extreme weather conditions. Extremely hot temperatures and heavy rain can increase bacteria counts that make people sick very easily. Moreover, the high temperatures might cause the disinfecting chemicals to react and produce harmful toxins
  • When the chlorinated pool water gets into your ears, it can cause extreme pain and swelling. Hence, it’s always a good idea to dry your ear after getting out of the pools. Besides, you can get earplugs or a swim cap to prevent water from going inside your ear canal
  • Take off your shoes or slippers before getting into the pool. They might carry animal feces contaminated with Cryptosporidium and other diarrhea-causing germs