Wiktionary
stomach bug
n. Something, such as a germ (colloquially a bug), that causes intestinal distress (particularly vomiting). Sometimes incorrectly used to refer to food poisoning.
Usage examples of "stomach bug".
Maybe it was just a cold, a virus, the lingering effects of bad water, some stomach bug.
Potchansky, claiming a stomach bug, then told the house's Prime-augmented AS to filter calls.
As for the stomach bug he'd picked up, he was hoping it would clear up now that he was back.
But I don't recall ever having seen you with a stomach bug that's lasted as long as this one.
Bobby Boy had a stomach bug caused by drinking from a cup that hadn't been washed up properly.