There is no mention of compression at this level but I wonder if your feeling pain associated with this disc bulge. A quick Google search shows that "there is a nerve that passes from the spinal canal through an opening in the back of the L5-S1 segment and runs down the back of each leg (as part of the large sciatic nerve). This nerve is called the L5 nerve root. It can lead to leg pain (sciatica) if any structure presses against it or if the highly inflammatory proteins from the inner portion of the disc leak out and touch it."

Are you experiencing any sciatic leg pain?