There is no such thing as ‘stomach flu’.
It is a misleading term that doesn’t make much sense when you think about it. Why is that? Well, ‘Flu’ is an abbreviation of ‘Influenza’, a respiratory illness of your upper airways. It is not related to intense, short-term bouts of diarrhea and/or vomiting experienced by your gut. These stomach illnesses are often caused by a food-borne illness bug called norovirus. Norovirus is transmitted by the contaminated feces and vomit of those that ill, usually by means of unclean hands and surfaces. Norovirus is sometimes called the ‘Winter Vomiting Bug’. Unlike the actual flu, norovirus cannot be prevented by vaccine. Frequent hand-washing is the only way to prevent norovirus. So the next time someone tells you they were sick with stomach flu, you can politely inform them they were not.
Click here for more info about norovirus.