My DD is 10 months old and started at nursery about a month ago. Naturally, she's been working through every bug on offer and so we've dealt with a stomach bug, cold, conjunctivitis and cough so far.
However, this weeks offering as me stumped a bit. Since the end of last week, she's been sporadically throwing up. It's nothing like when she had the sickness bug, she's eating and drinking well and her normal happy self. It's just that randomly, once every day or two, she'll just suddenly open her mouth and eject the entire contents of her stomach. 
It seems to be within an hour or two of her having one of the three 7floz bottles she has in a day. However it's not at every bottle, or the same bottle. It seems to make no difference whether she's sitting with someone or laying down for a nap.
I'd suspect an intolerance to something in the milk, but she's had the same milk since she was weaned off breast milk at about 7 months and never shown any problems before. Reflux was also raised by the nursery, but she's never had any problems with it before. An allergy to something else she's eating was also suggested, but there seems to be no common link appearing.
Has anyone got any ideas what could be going on and how to stop it from happening? Or could it be just another bug we need to wait out?