Re: parasites on diaper
I would bet that it is the cinnamon that is killing the parasites.
I am not at all surprised at the dr's, my son was allergic to wheat, when tested at the age of 5. I asked if he should go off of wheat, she said "no, we will giv ehim allergies shots instead"...duh! My DH had allergy shots as a child and they didn't do any good.
When she loses weight that is too late in my opinion, in a growing/rapidly developing baby that means loss of nutrients. you are smart in wanting to prevent that.
Try a sippy cut, with some stevia in it, with the probiotic (you can open capsules or get powdered). I did that with my kids. When they were older and reaching for my cups I would act like I was taking a sip, say "mmm, yummy" and then offer them some and say "mmmm, yummy" when they take a sip.
You can make your own non-milk kefir with juice, my kids were crazy about it.
Did they test her for ceoliac disease? What other symptoms does she have, besides the diareah and ringworm?
Looks like cinnamon is good for killing parasites:
http://www.colonzone.org/parasite-cleanse.php
http://www.crohns.net/Miva/education/articles/powerhealing_leogalland.shtml
http://www.herbwisdom.com/herb-cinnamon.html
http://www.inwardbliss.com/benefit-cinnamon.php