L5 and s 1 stenosis. Is it a permanent condition?

Depends. Lumbar stenosis is typically does not resolve on its own. It usually from hypertrophied ligaments or bones. If, however, stenosis is secondary to a herniated disc, this may resolve on its own. Discs have a fluid-like component which can dessicate over time, and as the disc dries up it lifts pressure off the nerve roots.