Actually Carol, discs very rarely "slip" or find their way back into place and you may have periods of less pain due to the lack of nerve immflamation, but what is generally happening is that the disc has herniated and the material of the disc is squeezing outward and pressing on a nerve. There are pain pills, anti-immflammatory meds, and cortizone, but at one point or another, you either live with the pain or have surgery.
There are a couple of differing surgeries depending on the cause and severity of the problem, the one being a fusion and the other a laminectomy. Docs would rather avoid surgery except as a last resort. In my case, I'd had problems (lower back) for 25 years by the time I was 40 and the last "go-round" ended with my almost complete immobility and constant pain that would not go away regardless of the med dosage and cort was a joke. I had a laminectomy (L4,L5,S1) and was fortunate to come out of it withy no side effects or problems and I rarely have any back pain now, unless I have to maintain the same position for hours on end.
I know exactly what Bill was talking about because even now its painful to lie completely flat and still for any length of time. CT's are tough for that very reason its also what makes heart catheterizations so tough for me. No pain, except for having to lie still and then be completely immobile for 4-6 hours afterward.