Dr Chris Steele discusses the notorious Winter Vomiting Bug (Norovirus). Norovirus refers to a group of viruses that are the most common cause of stomach upsets (gastroenteritis) in the UK. As these viruses tend to be more common in thr Winter months, and their symptoms are particularly virulent, Norovirus is normally refered to as the "Winter Vomiting Bug". Symptoms Obviously vomiting, often violent, projectile vomiting that can be very distressing to experience or witness. Also extensive diarrhoea. Fever and flu-like symptoms may also occur. Because immunity to norovirus is short-lived, both children and adults can be affected. This is in contrast to the much more serious rotovirus, which mainly affects children only.