So he needs to eat more hay, it will help pushing fur down, otherwise he gets blockages from fur and it is hard to pass. As i said baby gas drops or fennel/dill tea, massage his stomach, make him exercise so his gut is moving when he is moving.
What treats you mentioned, it is best remove all treats from his diet for now and reduce pellets, what vegs/greens you feed him now? Soak vegs in water before you give him and make sure he drinks enough.
You need to catch him and hold him and massage his stomach, give him gasdrops or tea with a dropper, later maybe crushed pellets soaked with water because he will stop eating if the blockages won't go out, and you will have to feed him manually.