poop

hi all here's a poop question

my 2 year old is constipated i don't know how to help her I've taken her off cows milk and I'm using lactose free milk her poos are normal colour and smell but they are like the size of a 10 cent pieces sometimes they are hard sometimes normal consistency

but always in round circles what can i do to fix this?! she poops 2 times a day sometimes she struggles to get them out

I've taken her to the doctor and he said its normal that her body is going through a change but this has been happening for a few months now I've used the laxative they give to kids her age didn't help

has any one else experienced this?!

thank you!!