Hi Eric
You have been through so much I am at a loss for words. All I can offer is my hope that something soon will "click" and give you some relief. For what it's worth, I have had very positive results eating one cup of cooked GF steel cut oatmeal every morning to thicken things up and avoiding all other carbs, dairy and sugar. I also take one packet of VSL#3DS every day. I don't know if any of this will help you but I thought I would pass it along.
Take care of yourself and hopefully you've already started to see some improvement or it will happen soon.