When Mitzi has a growling stomach she gets very scared so we give her 'beano' drops and after about 10 minutes the growling stops and she settles down. Maybe your little one eats a little to fast and gets a lot of air in his little belly. The yellow foamy vomit doesn't sound so good. Does he lick or chew somewhere where he shouldn't?
You could try a rice and chicken diet for a while.
