Have you had him checked by the vet for a UTI? That would be the first step. Is he going everywhere, or just in his crate? Some bullies can never have bedding in their crates.
If he has been checked,and pees in the house,not just the crate,I would crate him without bedding when you are not home,and leash him(holding the leash) when you are home,so that you can be sure to watch him.