Hi! I was diagnosed less than six months ago with Loin Pain Hematuria Syndrome (LPHS). I had every test in the book done before this: multiple CTs, ultrasounds, renalgram, every kind of blood work you can imagine.
It is a really rare disease that is prevalent (but not limited to) white women in their 20s. Not much is understood about it, but they think it has to do with improper diffusion of blood across the basement membrane of the kidney which causes swelling and the horrible pain.
There's not really a treatment, but I undergo nerve blocks every few months so I don't feel the pain from my kidney. It is amazing relief: such a difference from where I was last year.
I recommend looking up LPHS on the internet. I saw Dr. Hebert at OSU medical center and he diagnosed me - he's actually one of the doctors who discovered the disease.
NOTE: It is so rare many doctors have not heard of it. Press them to research it!