He might be too old for this, but when my dd was a newborn, she wouldnt suck at the breast & couldnt figure out how to get milk out. We used a 'primer' where we squirted milk in the corner of her mouth with a syringe while on the breast. She would get a taste of milk in the mouth & would suck a bit. We would keep squirting until she figured out to suck at the breast to get milk out. Maybe your ds needs a similar thing with the bottle if he wont suck to get the milk out? I would think if he is hungry enough, he will do it if he can figure out how?