Three year old Rio Poole from Bristol has been struck down with rotavirus not once but twice. He's not alone. Almost every child in Britain will have had the viral infection by the age of five. It's the most common cause of gastroenteritis in infants and very young children.
From September next year, infants aged between two and four months will be immunised against rotavirus - which causes diarrhoea, vomiting, abdominal pain, fever and dehydration.