Thanks for your query.
Noted the history of developing chronic diarrhea
after travelling abroad, particularly to India, stool test
was negative hence got treated as IBS as a blanket treatment. Condition worsened and the second stool tests showed Endolimax nana cysts . Although these are supposed to be non-pathogenic , there are reports on internet saying that these can cause diarrhea in some individuals...
As per the history you have provided, simple treatment with Metronidazole
should be sufficient to treat and see the results.
If there is still no results after a course of an antibiotic active against gastrointestinal infection
, I would advise you the following:
Stool tests for three consecutive days as at least one may show some other positive findings.
Tests of blood: CBC and particularly thyroid functions, diabetes.
CT scan of the abdomen as you are suffering for the lst 2 years, a long time to suffer. Colonoscopy
All these may give additional information for proper treatment.