My son has recently started retching and bringing up his meals.
He's been good with eating solids, but this is a new one!
HV (who is fab - I seem to have found a good one) says that he's worked out that he can do it, so he's just doing it cos he can. He's not unwell at all, or teething particularly, it seems it's just a bit of a habit or a new thing. 
HV recommended we go to finger foods and away from mush for a bit, which I tried today, but ds tried very hard and managed to bring up a bit of milk at supper!
Has anyone experienced this before? Any advice please...?