Odd gag reflex problem - any ideas what it is?

I told my PC doctor about this (he is an internist) and he didn't
really have much to say. A few years ago, I had a problem when I was
eating pretzels, and some tiny pieces of the very dry wheat must have
gone down "the wind pipe." I would have this immediate reaction where
I could not breath in more than a tiny amount of air, and this would
last about 2 minutes, and then it would just stop. It was a concern
because I was not sure what would happen if it continued beyond 2
minutes and I passed out. But then it didn't happen for a while, and I
got tired of pretzels, so it seemed like nothing to worry about. Now,
more than 2 years later, I had it happen to me again when a very small
amount of water (I was just taking a sip) went down the wrong pipe and
I had the same exact response. If anyone knows if there is a way to
stop this right away, rather than waiting the 2 minutes and hoping for
the best, please explain. Also, an explanation of what is going on
would be nice too.

Thanks

.