Shawnee Mission Community Health Update: Can swimming in the pool make you sick?

By Dr. Greg Sweat

With temperatures on the rise this week, it sounds like it will finally start to feel like summer. And where is the first place most families head on a hot day? The neighborhood pool. But can taking a swim make you sick?

Dr. Greg Sweat

It’s hard to believe that you can get sick from swimming at your favorite pool, but you can. Every so often we hear of an incident at a local pool that has caused many people to become sick. It is usually caused by swallowing water that has been contaminated with germs, which can cause diarrheal illness.

Swimmers share the water and their germs with everyone who enters the pool. On average, individuals have about 0.14 grams of fecal matter on their bottoms that can be rinsed off in the pool and, at times, contaminate the water. When someone who is sick with diarrhea gets in the pool, they can spread even more germs.

Swallowing even a small amount of contaminated water can make you sick. While chlorine does a great job at killing germs, it does not kill all germs all the time. Some germs take longer to die in chlorine than others, and cryptosporidium (a parasite that can cause gastrointestinal illness) is relatively chlorine-resistant.

There are other types of infections that can occur in addition to diarrhea, such as ear, skin and respiratory infections. Maintenance of the appropriate chemical levels in the pool is critical to prevent illness, but does not ensure that an infection will not occur.

The most common infection is diarrhea and can be caused by germs such as cryptosporidium, giardia, shigella and E. coli. Cryptosporidium or “crypto” is the leading cause of swimming pool-related outbreaks of diarrheal illness. Most of these illnesses will resolve on their own without medical treatment. However, if you develop watery diarrhea that does not get better in several days, talk with your doctor.

This doesn’t mean you should boycott your neighborhood pool. Swimming is a fun activity that can provide a great reprieve from hot summer days. However, there are some steps you should take to help prevent the spread of germs. Here’s some advice for all swimmers:

  • Swim diapers won’t protect us. Small children should take bathroom breaks frequently.
  • Don’t pee in the pool.
  • If you have diarrhea, don’t swim.
  • Shower before you swim.
  • Wash hands after changing diapers.
  • Don’t swallow the pool water.

This weekly sponsored Community Health Update is brought to you by Shawnee Mission Medical Center.
Greg Sweat, MD, is a long-time Prairie Village resident and Board-certified Family Medicine doctor at Shawnee Mission Primary Care, which has six locations throughout Johnson County. To find a doctor, call the ASK-A-NURSE Resource Center at 913-676-7777 or visit