Rotavirus is a nasty illness which causes vomiting and diarrhoea and fever. It can come on suddenly and last for up to 24 hours or longer.In come cases it can be present for up to 8 days. It is transferred through faecal-oral contimation. It is very common in younger children and is spread very easily. Some times its referred to as stomach flu although this is not a really illness and normally its caused by rotavirus. If you have children that have the illness then make sure that personal hygiene is to a high standard and reduce the risk of passing the bug on.