Does he drink a lot of liquids at night put a stop to it after the evening meal , tell him he doesnt need to drink a lot and if its soda they definatly make them go more. in fact even the last meal shouldnt be late, I would do away with the pads or pullups, it is enabling the issue and may be he can help you wash the sheets each day, let him take control of his own body , say less and dont feed into it,it gets a lot of attention and there could be reason there Focus on his positive side .