You will be in my prayers, I am so sorry you are having so much pain, and even more frustrating to not know what it is.
My aunt went through something similar last year, and it was further advanced on her, but her brother and my mother both have the "intestinal problems" also. They all had colonoscopys, and my mom told me it really wasn't that bad, she didn't even know what was going on.
I'll keep you in my thoughts, and hope that they find out what is wrong, and that you are out of pain soon.