Are you seeing House now? Sounds like something he might do. He never is satisfied with the other doc's diagnosis. Not even his own. When does your episode air? Seriously, I imagine you must be getting very frustrated with this medical merry go round. Haven't you been diagnosed with RA, Crohn's, neuropathy and I can't remember what else.
My hairdresser's son had been to all sorts of pediactric GIs and given all kinds of invasive tests and inappropriate diagnoses. She took him to Mexico (she's from there and goes to visit her fam frequently) and the doc there said it was a parasite, gave him medication. He took it and is playing football now. No more problems. I'm not equating his case with yours, but hey if it is some little creature and they can politely or not so politely ask it to leave and you are better, that would be a good thing. Besides we all have little residents in our bodies. Some are good guys, some aren't. You just gotta hope the good guys outnumer the bad. I could get pretty philosophical about this so I better close. Oh, check out www.despair.com. Should give you a good laugh.