Hi. Sorry you are having this symptom! It "could" be worms. I don't know if you can have them from birth, but I searched on "white rice in stool" and saw this link to tapeworm, which woud certainly explain the hunger issue you are having, along with the bloat, IBS, etc. And it would explain why the candida diet is not working - I have read many times here that parasites need to be dealt with first.
You should ask your Dr. to run a test for parasites. If he will not, I "think" you can self-order a test from Great Smokies lab (Google their website).