Are
recreational water illnesses causing your gastrointestinal issues including diarrhea? Maybe. They spike in June, July and August for obvious reasons. Recreational water illnesses (RWIs) are caused by germs spread by swallowing, breathing in mists or aerosols of, or having contact with contaminated water in swimming pools, hot tubs, water parks, water play areas, interactive fountains, lakes, rivers, or oceans. Diarrhea is one of the most common symptoms.