can you mix formulas?

[mustbemadno3]

Ive been combined feeding (breast and bottle) but unfortunatley 3 weeks ago had to stop breast altogether. I feed my baby girl (13 weeks) sma gold which she has been fine on. But she has recently started waking during the night every 2 hrs, where as she can normally do 4-5 hrs.
I gave her the hungrier baby milk at 6.30p.m and she didnt wake until 2.00a.m and then 7.00a.m it was bliss! I have fed her gold again throughout the day. However, she has been very unsettled this afternoon, seems quite colicky and crying alot.
So I am wondering is this because I mixed the formula?
I have looked this up on the net and some people say you can mix the 2 formulas in the same bottle to help introduce the other milk?
Am I doing the right thing giving it too her at all?

mustbemadno3 - there are a couple of good leaflets here which give info about different types of formulas.

Have a look at those and then maybe have a chat to your HV.

It's usually best to stick to one or the other as they are based on different proteins with stage one being easier to digest. IME it takes a few days to get used to the different milk, I was told not to mix stage on and two - stick to one or the other for every feed.

Also the hungrier baby milk is thicker so it might be worth trying a medium flow or variflow teat so it's easier for your dd to get the milk so less air is swallowed.