Actually, the doctors all seem to have no real answer. Or saying spinal stenosis can cause this - and I have had spinal stenosis - however, I've had a lumbar 360 - followed 2 yrs. later by surgery on the L3-L4 ---- (during which they removed some of the pedicle screws from first surgery.) I have had sonograms of my legs with the diagnosis of venous insufficiency in left leg. It retains a lot of fluid. But I feel they are only doing the sonograms on my legs and my pain is up in the buttocks areas. How, rather where would they test for claudication affecting the buttocks? Yes, I've been to several physical therapists over the ten years but none of them have been able to help me. It's not just tight muscles as one doctor recently suggested - as I've had therapists to put me through so many stretching exercises without any help. I do have a recent RX for stretching those muscles again - and doing water aerobics - probably due to my spinal surgery still being fairly new. (3 months) Thank you for helping me with this. Your words make me wonder about my blood not carrying enough oxygen to the buttocks area. How would they check that? By the way, I have an appt. with a rheumatologist next month.