Recurrent sickness

[Daisypod]

My 3 year old threw up Wednesday evening, twice and quite violently.
We assumed it's a bug, no worries. He didn't eat much yesterday morning but by the afternoon he had several snacks and some dinner.
This morning he hasn't had his full appetite but has been eating. This evening, literally 48 hours after the last bout he's been sick again! Dh had offered him a bite of his flapjack and suddenly it was like a fountain again!
I have five children and he's the youngest and I've never had this happen before. They've been sick and off their food then after a couple of days back to normal.
Could this still be a bug?

This happened to my son recently. He had sickness, then he seemed to pick up and started eating. 48 hours sickness and diorehha again :( I put it down to his tummy just not being settled properly... but it did take me by suprise hope your little one is ok 🩷

Thanks, he seems fine now but it's so sad seeing him so upset, he's autistic and doesn't have the understanding or language of an average 3 year old.