What is this “sliming” stuff and what makes it happen? If I've eaten too much or didn't chew very good - I get this slimy stuff. What could it be?

If you are 'stuck' your body sends lubrication to try to help the food pass through the banded area, or its anticipating that we will soon vomit it up. Some call this "PB= productive burp" I'm 16 months out and only had it happen to me once, and it was not burp like to me. Either way, the saliva, or.. "slime' backs up into our throat. If it's bad, I stand over the toilet or garbage and just keep spitting until it stops. But if I'm not too terribly stuck, I have found if I lay flat on my back on a hard floor, I will stop sliming and the item will usually pass without vomiting. Good luck!