Those little yellow guys are a bit controversial. I think some folks believe they are candida or a sign of candida. My colon therapist (whom I saw yesterday) said they are mucus and usually come at the end of a colonic, getting pulled off the colon wall.
Maybe it's a little bit of both.
I will be curious to hear more from our resident experts!
BTW, I am in the middle of my second flush (the easy part! The morning after)