I've had lower back issues with siatica since the 90's.  In 1998 I had a microdisectomy on my L5-S1 disk to alleviate a ruptured disk.  However, the pain will develop whenever I stop keeping my core strong, stretching and staying active physically.  Yoga always helps and doing crunches/stomach exercises keeps the core strong enough to support my spine.  Maintenance seems to be the key ingredient.