We started top ups in hospital - NAN and S-26. Then BF for a week or so, then we comp fed - I had quickly read about formulas at the last minute so he then went on NAN HA its easier to digest and not as filling as S-26 so it worked well and he is still on it.

I bought a tin of Bellamy's Organic on special, but he was only 4 weeks old and he spewed up a lot. I think your GP is wrong if you chop and change them on different formulas, they become more spewy imho. Better to stick with one where they are chucking up a little rather than swap around.