The most common cause of upset stomachs in the UK is from a viral infection called Norovirus. This is also known as the ‘winter vomiting bug’ and has been responsible for large outbreaks and the closure of hospital wards.
Symptoms normally only last for 24 to 48 hours, and recovery is usually quick. It is not necessarily associated with eating contaminated food. It is easily passed from person to person, so strict personal hygiene standards are necessary to prevent it from spreading.