I used not to feel comfortable to advise for kids. They are growing up and there is a lot to consider. You did the right thing, live/dried blood cell is a great way to see what is at stake.
Overall with candida, the problem is we do not digest well enough. Myself, I have identified candida as the culprit in year 2000 with a heavy case of chronic fatigue. I went back to a normal diet twice, and candida came back twice. So I have tried quite many things and I believe I have the know how.
But first tell me:
Do you do enemas? How many bm/day does he get normally? with the cal-magnesium supplement?