Goodness, so much to add, but the forum's been down so I haven't been able to =P
The other urine test didn't show anything either. She told me she couldn't do the KCl test but was able to refer me to a urologist, who I saw this afternoon. His name was Dr. Coons and he was very nice and understanding, and upon asking him about the test he said he didn't like doing that test, as it was inaccurate (from what I've read, it's only 60% accurate, so he's not wrong there), and said he really did not want to stick me with a diagnosis of IC (from his tone, I'm guessing it's because IC really sucks to have, and not him thinking that's not it). I had peed in a cup (yet again) before seeing him (which, again, showed nothing), but he stuck a catheter in me to see how much urine I was still retaining (and to see if there was anything physical, like a blockage, causing my symptoms, which there wasn't), and he managed to get out about 120 cc, "which is more than I like to see," he admitted. He said retaining that much puts me at risk for repeated UTIs, and he still didn't quite have a good idea of what could be causing my pain and burning and assorted stuff down there. In the meantime, he gave me a prescription for Prosed DS and is hoping that will help relieve those. He said he'd like to see me back in three months and if things haven't resolved by then, he would like to put a scope up there (a cystoscopy; no mention of hydrodistention).
So yeah, all I know for sure is that I have urinary retention, which, well, gee, I could've told him that =P And speaking of the catheter...as bad as it felt going in, it was even worse getting pulled out, LOL! Everything I learned from watching ER is true! And it was strange...shortly after he pulled it out, I had the urge to pee, even though my bladder was most certainly empty at that point!