... including upper gi, I can eat very small portion of food, or even a drink of water, and up it comes, out of the blue, no signs or symtoms (symptoms), I feel full after I drink 4 or 5 drinks of water to where I can not drink another drop same with food. Up it comes, not just a small portion, but alot. I am embrassed to go anywhere cause you never know when its coming. PLease any advise to what could be the cause.