You think your dog is bad, try hanging out with Boston Terriers for a day.. LOL they can clear a room fast.
Ok food, you can try to switch them to something a little more for sensitive stomachs, IE Eagle Pack, oatmeal and rice. Also if you think their gas is worse now then maybe it was before, then you might want to consider getting their anal glands expressed, I know it's gross but some dogs need to have it done.