J.P.
Just reading the first sentence, I hadn't even gotten to the stuffy nose part, but I was going to say, maybe they can't adequatedly breathe through their noses. I find the more dairy my kids eat, the more they chew with their mouths open. Because dairy causes increased mucus production, I find that it takes about a week ro more of no dairy before they really start to be able to not chew with their mouths open. Even if they don't sound stuffy, they may have swollen sinuses, etc. I also find that PB8 from Nutrtion Now helps a ton with the stuffy sinuses.