There are several different waterborne germs that can lead to gastrointestinal (GI) illness. These illnesses may lead to diarrhea, nausea, fever, stomach pain, and other symptoms. Germs causing GI illness may be found in treated or untreated recreational water, like pools, hot tubs, splash pads, oceans, lakes, rivers, and sprinklers.
- Waterborne GI illness is caused by swallowing contaminated recreational or contaminated drinking water.
- Swallowing contaminated water could happen through:
- Drinking untreated water
- Unsafe well water
- Swimming in contaminated treated water
- If someone is having diarrhea and goes swimming, even a speck of feces left on their body can contaminate the water
- Accidentally swallowing contaminated water
- Bodies of water, such as lakes and rivers, can be contaminated with animal feces, sewage spill, and runoff water
- Eating food that was contaminated by an unsafe water system
- Such as a sprinkler system that waters raw fruits and vegetables with contaminated water
Waterborne illnesses can cause a variety of symptoms or no symptoms at all. The most commonly reported symptoms of waterborne illness can include the following:
- Diarrhea (≥ three loose stools within a 24-hour period)
- Vomiting
- Nausea
- Stomach cramps
- Fever
- Skin, ear or eye problems
- Cough and/or shortness of breath
- Stay out of water if you are experiencing diarrhea or vomiting
- Avoid swallowing water while swimming
- Limit water entering the nose while swimming in warm, fresh water
- Wear a nose plug when entering bodies of water
- Ensure frequent diaper changes and restroom breaks for people who wear diapers
- Do not drink from untreated or unknown water sources
- Ensure building owners and managers maintain treated water systems
- Shower with soap and water before swimming
Conditions that come from water contact:
- Amebiasis (Entamoeba histolytica)
- Campylobacteriosis (Campylobacter)
- Cryptosporidiosis (Cryptosporidium)
- Cyclosporiasis (Cyclospora)
- Giardiasis (Giardia)
- Leptospirosis (Leptospira)
- Primary amebic meningoencephalitis (Naegleria fowleri)
- Shiga-toxin producing E. coli infection
- Shigellosis (Shigella)
- Norovirus Infection (viral gastroenteritis, Norwalk virus, calicivirus)
- Vibriosis (Vibrio/Cholera)
General Healthy Swimming CDC Tips
Prevention
- Preventing Waterborne Germs at Home
- Preventing Drinking Water-related Illness
- CDC Swimming-illness Prevention
- Preventing Illness While Camping, Hiking, and Traveling
- Preventing Recreational Water Illness
Water Safety
- Testing and Disinfecting Private Wells
- Find a Certified in State Drinking Water Laboratory
- Flood Health and Safety
- How to Avoid Contaminated Water While Traveling
- How to Safely Visit Oceans, Lakes, and Rivers
- For Swimming in Pools, Hot Tubs, and Splash Pads
- Information About Chlorine and Swimming
Agricultural Water
Condition Specific Guidance and Prevention
Page last reviewed/updated: March 2025
