Dh and I had the tummy bug D & V thing last week and DS (1) was also sick about 5 times during the first day. In between he was fine (not like us who felt like death). Since then he's been sick every other day, mostly after a bottle. A couple of times it's been a torrent. Once he's cleaned up he's fine and generally, apart from being a bit off his food (he's also teething so that doesn't help), he's his usual cheery self.
When he was a baby he had reflux and was on gaviscon. It didn't properly go until he was about 9 months. His recent sickness is very much like it was then.
Could it be that the tummy bug last week has aggravated his reflux and brought it back? We've started add Gaviscon back to his bottles again. The doctor was not really concerned as dh was sat there grinning (little monster!).