When I began going off of gluten I briefly considered getting tested. I ended up not doing it because they would have pretty much just told me what I already knew. I hate seeing people go back to being in pain just to have a doctor confirm.
But to answer some of your questions.. there is no way to reduce the pain, really, and I'm pretty sure you have to eat a lot of gluten before you get tested. I'm not certain, though, I never spoke to a doc about it but you should be able to ask yours.
As a side note- I have discovered that when I accidentally eat gluten if I eat a lot of other filling food directly after that, it will tone down the pain a bit. This isn't something that would help if I were eating it consistently, though
Good luck w/ whatever you choose~