We used nan ha gold, and Heinz when the boys had top ups.

They say to give it a week but I'd it's making your child constipated or sick I don't know if I could.

Try one of the HA formulas they are less likely to make your child constipated and are more easily digested.

ETA:chucking up may be unrelated to the formula too so it's worth having it checked out if it continues, there are a few things it could be.