I was just curious, is gagging on food a sensory issue or is it just that he's not use to the taste, texture?

it's part of food aversions & reflux but I guess could also be a sensory issue as well. Eliana gags on food alot especially if she doesn't like the texture

I don't think Owen ever gagged on the purees when I thickened them with cereal. But once we started the stage 3 with chunks he was gagging like crazy and ended up vomiting a lot of the times.
What if you just try about 1/2 tsp and see how he does and once he gets used to that increase it a little at a time. You could maybe use a puree stick and make it more smooth.

Gagging can be reflux related, but I don't know about the sensory thing. Noah has a very strong gag reflex.

BUT, gagging is also a very normal thing for normal babies when trying new foods.

From what I've seen, it's a reaction to new textures, sizes, etc. Joshua does it until he gets used to what is in his mouth or spits it out.

The whole gagging thing was brand new to me with Evan, as Brandon never gagged, except when trying his first few bites of infant cereal the first time. Eliana's Mommy is correct that gagging often goes hand in hand with reflux, but that it can also be a sensory thing.

I tried the squash again yesterday without thickening it and he ate it fine with no gagging. He just doesn't like it with the rice.

Honestly, I think some kids just have a strong gag reflex and as the ped. described it to me, it can be more of a "yuck" reaction than any actual problem. That mades sense to me, so I went with it, then the GI confirmed it. With babies with strong gag reflexes, then when they do the "yuck" face and stick out their tongues just a little, then the gag reflex starts and in Cady's case, her gag reflex was so sensitive, she'd gag then vomit on things she didn't like and some things like stage 3's. However, at the advice of the ped. and GI, I kept giving her even the foods that made Cady gag and puke and after 20 or so (very messy) tries, she liked that food and no longer gagged on it.