Hi tiredredhead, the pain your describing is very much like the pain I have, and it is from a herniated disk at L4/5 and I also have severe narrowing of the framin (the
openings in the vertabra that the nerve roots from the spinal cord pass through) any way that is putting pressure and impinging on the nerve root, but typically the pain felt from that is further down the nerve path way, such as in the buttocks and down the leg. You can have it on one or both sides depending on what is being impinged, if the nerve root is being impinged on the right side then that is the side you will have the discomfort. For me they are going to do a laminectomy and framinotomy and diskectomy at L3/4, and L4/5 on the right side and the same procedure at just L4/5 on the left side, I am scheduled for the surgery the ninth of January. I have had three fusions in my neck and the first herniated disk I had was at C6-C7 the pain I felt was from my elbows down into my fingers, but not in my neck but the pain was on both sides because the disk was pressing directly into the spinal cord causing impingment on both nerve roots on both sides. The second time it was herniated at C5/6 but the pain was mostly in my left arm because the nerve root on that side was impinged the worst. I had a Anterior Cervical Diskectomy and Fusion done on both of them.
Anyway your complaints of pain in your butt and thigh sound very similar to mine, and it sure sounds like problems with your lumbar spine. I do wish you well and hope you can get some answers soon!
White Beard