Disc Pain: 
Here, you have the opposite effect.  Now, the actual space between the discs, or the fluid sack there, is where the pain is originating from.  This is one of the main causes of lower back pain.  This is known as axial pain as there are no nerves being pinched.

Why Is This Important?

Why is it so important to know what is causing the pain here?  Knowing what is causing the pain specifically will help you to know what treatment options are available to you.  The treatment options between a pinched nerve and a disc pain situation are quite different and knowing the difference can help you to understand the right method for treating the condition. 

Your doctor will help you to overcome the various steps in diagnosing these conditions to determine exactly what you are suffering from.  Together you can work out a treatment plan to overcome these problems.