Happyballerina, just a thought - perhaps you could explain a little more about your symptoms to the nurse and ask for some medication for symptom relief (Zofran for nausea, Lomotil for diarrhea, etc). At least then you'd be a bit more comfortable until you can get back to the US and pursue a diagnosis and you likely wouldn't end up in the hospital. Obviously meds like that will only take care of symptoms and not the underlying illness itself, but hopefully something like that would be enough to get you through the next few weeks. I'm glad to hear your mother is so supportive and is contacting your doctor at home about this. I hope the next few weeks aren't too awful and that you can get things figured out quickly once you get home!
Rose, refresh my memory, have you already had a colonoscopy? Flexi-sig is not a useless test, but colonoscopy is much more thorough. The benefit of flexi-sig is that, as you said, they can do it right there in the office. But it doesn't go in nearly as far as colonoscopy does so they won't see as much. If you haven't yet had a colonoscopy, particularly if the flexi-sig doesn't find anything, I would definitely ask them to schedule a colonoscopy as well.
Leanne, I wish I could answer your questions, but I don't know much about parasites. And without knowing the name of the parasite, I can't even google it for you. I think you need to call your doctor and ask a lot of questions, like what is the name of the parasite, why would it stay in your body for so long, what symptoms can it cause (is it likely causing your current symptoms), what is the treatment for it, etc.
How's everybody doing today? I'm kind of bleh. I had a good day yesterday, but today it feels like yet another migraine may be starting and I am also feeling a bit nauseous. I'm so sick of having chronic migraines! It's a side effect of the Entocort that I'm currently taking, so I need my guts to hurry and heal so that I can get off the Entocort and stop having so many migraines. Ugh.