Check out this study: bulging discs are normal
The typical experience of chronic back pain sufferers goes like this: History of intense pain, spasms, reduced physical activiy. Go to the doctor. Get MRI. In most cases the imaging will reveal some kind of disc "abnormality." The doctor will see this and make his diagnosis. The fact is that most of these so-called abnormalities are actually quite normal and harmless. They cannot neurologically account for the pain that is felt.
The prevalance of back pain has dramatically increased since about the middle of the 20th century. The human back is not that fragile. There is no organic structural reason for an otherwise healthy person to spontaneously be crippled by spasms from harmless activities like bending over, sitting, "sleeping wrong," etc...
The cause of pain in most cases is emotional (primarily repressed anger). Once you realize this, your pain will cease.