Do you use follow on formula?

Ra
Has anyone changed their babies into stage 2 (follow on formula)?
Would you advise it?
My son is 7 months and he's on cow & gate comfort formula. I was going to change him to the normal stage 1 formula as he no longer needs the comfort milk (it's now causing loose dirty nappies and his colics gone). My health visitor said he didn't need follow in formulas at birth just to stick to stage 1.