My 34 month old is severely constipated. Anyone have any thing I can try that I have not tried already?

My daughter drinks prune juice everyday and this works well for us, I always give her a salty snack with it to make it taste better. Also, try to give her lower fat foods, high fat foods can make it worse. She should drink a lot of water too. The more fresh fruits and veggies the better. Hope that helps!