Your baby's body is pushing it through to get it out. He isn't ready. It is totally normal for him not to be digesting these foods at this point. Heck, my 11 m/o isn't even into pureeds more than a few bites.
He never liked pureed foods (can't blame him :LOL ) so we just let him choose what he wants off the tray. He puts these things in his mouth (and doesn't make a face anymore) and some days puts them in with great gusto! And sends them out with great gusto to.
well that's a big reason why we don't do it (pureeds). I agree that he probably isn't digesting them well either. But it is already masticated and therefore I feel it is okay for him to taste for fun.
Actually I do look at my poop
My point is that he should be able to mush/chew things up. The mouth is the beginning of the digestive process. Also the fact that some of these foods are being pushed out quickly indicates the body's need to get rid of it. Just because a baby will put things into his mouth and swallow them doesn't mean it is beneficial. Mulch, rocks, dog hair...
My DD only has 4 teeth and though she definitely chews, she doesn't always chew stuff up beyond recognition. At 14 months she still eats a very small volume of solid food and much of it comes out almost unchanged in the diaper.