Hi, just thought I would chuck in my two cents worth!

Just out of curiosity have you had/know the results of the straight leg raise test and slump tests? I'm pretty certain this would have been done? Also is there any weakness, numbness, pins and needles in the left leg compared to the right? If there is a true nerve impingement on the nerve root you would expect some neural symtpoms and reduced reflexes.

From my experience with chronic disc bulges like yours, I find many patients have developed adaptive posture into a overly anteriorly tilted pelvis as this would have been a position of comfort initially, as such patients lose the ability to posteriorly tilt their pelvis which is needed during normal lumbosacral movements i.e bending forwards and backwards. Also due to this constant anterior pelvic tilt more pressure is put on Z-joints in the lumber spine so they can become irritated and also this explains when you bend backwards the pain is increased or 'pinching' as the joints are already near the end of their range and you are just really shutting them down on further extension. This theory would also explains why sitting is a position of comfort for you and standing/walking is worse, which doesnt really fit the picture of a disc problem anymore!!

In terms of treatment I agree with guy below in getting a release on the hip flexor muscles as well as the quadratus lumborum as these are the muscles that would become tight in a chronic anteriorly tilted pelvis, once released (and continuing with stretchs) work a lot on regaining your posterior pelvic tilt in lying, sitting and standing so that you adapt back into a 'normal' position for your back and pelvis to work better together.

As physiobob said, time is a great healer and after two years I would expect the disc to be in a stable state so infact you would want to promote opening up of the joint (lumber flexion) over closing them down further and compressing the nerves with more extensions!

Hopefully this makes sense, you seem quite in the know so should do! Hope its of benefit! If not and in view of your new actue episode, maybe a new Wikipedia reference-linkMRI is in order to see if something has changed causing the new onset!

Glenn