Rotavirus is a microscopic organism that is best known as the most common cause of acute gastroenteritis seen in children. Acute gastroenteritis is the term used to describe sudden onset vomiting and diarrhea in children. With rotavirus vomiting typically lasts 2-3 days, and diarrhea usually lasts 5days, but these are just averages and are different for every child. Other common symptoms include fever, and respiratory symptoms (congestion, cough, sore throat, etc).Ear infections and pneumonia can even be associated with rotavirus. Nevertheless, by far the most common ailments are related to the vomiting and diarrhea.

There are other infections and noninfectious causes of vomiting and diarrhea, and sometimes it is not easy to sort out exactly what the cause could be. Green vomit, blood in vomit or in the diarrhea, and severe, or persistent abdominal pain are always reasons for urgent medical evaluation.