I was private. I went the GP multiple times and was told it was old age (39) and that the excruciating pain in my leg was due to nerve damage. He said the back pain was caused by the leg pain. The words were basically go away and get used to it. After being in absolute agony for a month, I finally forced the GP (another one) to refer me to a physio privately. The physio said I had the worst locked back she had ever seen and the most curvature caused by compensating for the pain. She tried treating me just for 2 sessions and then wrote a strongly worded letter to the GP telling him to refer me to a spinal consultant. It took me a 3 attempts to get the GP to refer me, eventually it was a locum who did it without much bother. The minute I walked into the consultants office he said he knew what the problem was. I had a variety of tests including an MRI. He suggested some non-surgical treatment called IDD which is basically being stretched on a rack.
http://www.chiropractorswarwick.co.uk/index.php/idd-therapy-spine/ I tried 20 sessions of this together with chiro and sports massage, but although I had some results they were not good enough.
A second MRI followed and surgery was immediately planned as it was thought that by leaving it too long I would suffer permanent nerve damage. Surgery was performed, as soon as I came round I felt pain free for the first time in over 6 months. It was bliss. Since then I have not looked back (pardon the pun).
So - yes, it was private and expensive, my experience with the NHS was horrendous and I wait for the day this particular NHS doctor retires. I and my family refuse to be seen by him now.