If you’ve got a dodgy tummy, diarrhoea and have been vomiting, it’s easy to blame a “tummy bug” or “off food”.

But which is it? Gastro or food poisoning?

What’s the difference anyway?

Gastroenteritis, or gastro for short, is a gut infection caused by a virus, bacterium or other microbe.

The gut is teeming with cells including healthy microbes and the cells lining the gut. But when viruses, bacteria and other microbes start to invade your gut, they colonise, build up in large numbers and eventually cause the cells lining the gut to inflame. The “-itis” at the end of gastroenteritis means inflammation.

Gastroenteritis is extremely common. In Australia there are an estimated 17.2 million cases a year.

So where do these gastro-causing microbes come from? Eating contaminated food is often the source.

However you can acquire these microbes in other ways. For example, if you touch a surface where someone sick from viral gastroenteritis had vomited on, that virus could transfer to your hands. And if your hands touched your mouth, you in turn could contract viral gastroenteritis.

Food poisoning refers to getting sick from eating food contaminated with chemicals, microbes or toxins.

For example if you ate food contaminated with insecticides or methyl alcohol (

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