Preventing Diarrheal Illnesses

Key points

  • Diarrhea is the most common illness reported in outbreaks linked to water in pools, hot tubs, splash pads, oceans, lakes, or rivers.
  • You can get sick with diarrhea if you swallow contaminated water in these recreational water places.


When you go in a swimming pool, hot tub, splash pad or other recreational water venue, you can swallow germs that cause diarrhea like Crypto, Giardia, Shigella, Norovirus, and E. coli O157. These germs can survive in properly chlorinated water for minutes to days, depending on the germ.


If someone is sick with diarrhea and has an accident in the water, millions of diarrhea-causing germs can get in the water. If another person swallows even a small amount of that contaminated water, they can get sick. Germs can also get in the water from small amounts of poop rinsing off swimmers’ bodies.

Filters and disinfectants (chemicals like chlorine or bromine) work together to help kill germs. Filters remove debris (such as leaves), which can use up the disinfectant in the water that is needed to kill germs.

Pool staff make sure chlorine or bromine is at the level needed to kill most germs in the water within minutes. However, you can still be exposed during the time it takes for the disinfectant to come in contact with the germs and kill them. You can also get diarrhea from germs that are hard to kill, such as Crypto. Crypto can stay alive for more than 7 days, even if the water is properly disinfected.

Facilities with multiple pools often use one filtration system for all of the pools. This causes water from multiple pools to mix and means that germs from one person's body could contaminate the water in more than one pool.

Prevention steps and strategies

We all share the water we swim, play, or relax in. Each of us can help protect ourselves, our families, and our friends from germs that cause diarrhea.

Take the following steps when swimming or playing in the water:

  • Stay out of the water if you are sick with diarrhea.
    • If you have Crypto, don't go back in the water until 2 weeks after your diarrhea has completely stopped.
  • Don't poop in the water.
  • Don't swallow the water.
  • Take kids on bathroom breaks and check diapers every hour.
    • Change diapers away from the water to help keep germs out of the water; wash your hands after.

Before going in pools, splash pads, and hot tubs, rinse off! A one-minute shower will remove most of the dirt, sweat, and oils on your body that use up the pool chemicals needed to kill germs.