I can't remember if it's normal for formula feed babies to have runny poos and how many they should do ?

Since changing Eleanor from S26 AR to Karicare AR she has had the most awful runny poos.
She didn't have runny poos on the S26 AR but she was still throwing up.
I have had her tested when she was 6wks old to see if she was lactose but that came back normal.