First and foremost, if you're having lower back issues definitely get them checked out by a medical professional. In the meantime, most lower back issues are not all created equally, and some of them will go away with the proper exercises. Even if you've been working out for awhile, it doesn't hurt to add these exercises in, a strong core equals better lifts!
Lower Back Routine:
Back Extensions - 2 sets of 10, rest 60sec between sets
Superman - 2 sets of 10, rest 60sec between sets
Knee To Chest - 2 sets of 10 each leg, rest 60sec between sets
Cat Stretch - Place hands and knees on the floor, so you're in a tabletop position. Push your upper back into the air into a hunch-back position, hold for 20-30sec, then drop you upper back and lower back muscles toward the floor, hold for 20-30 Sec. 2 sets, rest 60sec between sets
Try these for the next 30 days and you should see huge improvements in your lower back and your lifts!