I've just been diagnosed as having Blastocystis hominis. It only came up positive after getting tested at a specialist lab for it, and all the other infectious disease labs could not suggest anything. I would recommend getting tested for Blastocystis hominis and Dientamoeba fragilis. Lots of information on the 'badbugs' site- search it on google. I haven't been treated yet but really hoping this is the thing. Good luck!