Norovirus. With norovirus — the most common cause of viral gastroenteritis

in adults — you're contagious when you begin to feel ill. Symptoms usually appear within one to two days of exposure. Although you typically feel better after a day or two, you're contagious for a few days after you recover.

Can you catch a gastro bug?

The bugs that cause gastroenteritis can spread very easily from person to person. You can catch the infection if small particles of vomit or poo from an infected person get into your mouth, such as through: close contact with someone with gastroenteritis – they may breathe out small particles of vomit.

Is the stomach bug contagious through air?

Another way to catch the stomach flu is by breathing in airborne viruses after an ill person vomits. If the illness is not quickly recognized and steps immediately taken to control it, the infection will spread rapidly from person to person.