spinal disc herniation, colloquially called a "slipped disc", is a medical condition affecting the spine, in which a tear in the outer, fibrous ring (annulus fibrosus) of an intervertebral disc allows the soft, central portion (nucleus pulposus) to bulge out. This tear in the disc ring may result in the release of inflammatory chemical mediators which may directly cause severe pain, even in the absence of nerve root compression (see "chemical radiculitis" below). This is the rationale for the use of anti-inflammatory treatments for pain associated with disc herniation, protrusion, bulge, or disc tear.

Pretty much what I'd read on innumerable websites while doing my research, but the verbage was slightly different from what was used during my initial diagnosis last year. The first go-round was a large, free floating fragment, obviously the result of a herniation. It had nearly closed the formaninal opening, and had severly displaced the S1 nerve (hence the "classic" signs I exhibited). The initial surgery was just over 11 months ago, and at some point between last September (my "all clear" MRI) and the MRI last week I managed to rack up another "protrusion". Fortunately, I don't seem to be syptomatic, though I'm a bit concerned that his one was in a different direction from the first (ie original = left side, current = central/right). Keeping fingers crossed my Primary Care Doc can get me on the right track, and I can improve with conservative treatment....