fledgling
Oh dear...I just hate it when someone asks an intelligent question and no one has an intelligent answer...immediately!
Personally, I haven't used those meds, and I would be quite reluctant to...I'm chicken.
I read somewhere that there is a kind of 'incubation' spot in the lower colon where some parasites like to live.
And, I've heard that there are thousands of varieties, many of them microscopic. (70%?)
If you are feeling something anally, I would suggest diluting some of R.G.'s cream with a little coconut oil, or some other suitable cream, for external application.
I'd reapply it several times through the day...see how it works.
It seems that it must be a parasite which can be washed away with water in an enema...so you have figured out that much. Good for you.
I wish you luck with your program.
Fledgling