Shin Splints. (I'm not a doctor, just a runner)
I've been running all my life and have battled shin splints until 2 years ago, when I changed my running style. I used to be a heel-to-toe runner. Now I'm a forefoot runner and run 6 to 8 mile trail runs 3 to 4 times per week. I don't have any shin splints or lower back pain anymore.
I believe the best thing you can do is change your running mechanics. Shin Splints come from the abnormal impact of your foot on the ground. When you run heel-to-toe, your leg is completely extended on impact with the ground, causing all sorts of problems (shin splints, knee and back pain). Try shortening your stride and running on the balls of your feet and not extending your leg completely (Kenyan marathon runners are the best at this because they grow up running without shoes, on the balls of there feet). This is actually the way your body was meant to move. Your ankle, knee, hip provides a shock absorber for the body.
It's a bit awkward at first, but you'll find the shin splints start to go away. You're calf muscles will be very tight for a week or so.

Sorry if this has already been covered.
Good Luck.