We use Actilax too, but thankfully after years of constipation we are finally getting some musshy poos. My paed told me..after I freaked about having to give her a dose daily that keeping the poos soft and passable without stretching the bowel is a far better way to go than stopping the med's. But then again he also told me when she went on to solids that it would get better and it got worse.
I'd get a referal to a specialist just to have a chat
Bec