Can you go into more detail about the test you took?
Odds are just the flagyl itself did not cause the candida, but other parasite/medicine/environmental factors to mess up your intestinal track.
It is all tied into the reason you found this forum to begin with.
I would work on getting rid of all pathogens and try restoring the balance of your immune system. (Way way harder than it sounds, trust me, i'm working on it :)