Going to the doctors.

Hello all,
Well my GP has still not found anything, but ill say one thing, at least he keeps on trying, and not giving up on me.
He is now sending me to another specialist, he wants me to be checked for Giardia.
I was wanting to start a round of Ivermectin, and albendazole, but i think maybe i will be checked for what these kill before i start.

My question, what are the best tests i should ask the doctor for ? To check me for, giardia, parasites, or candida ?

Thanks to all in advance.