Almost all kids have had a rotavirus infection by the time they're 5 years old. Rotavirus is one of the most common causes of diarrhea, and severe infection (rotavirus gastroenteritis) is the leading cause of severe, dehydrating diarrhea in infants and young children.
Rotavirus infections are responsible for approximately 3 million cases of diarrhea and 55,000 hospitalizations for diarrhea and dehydration in children under 5 years old each year in the United States.