DrugBuyers.Com: BACK SURGURY- good or bad idea?

Can anyone tell me if they have experienced anything similar to this?
I had a spinal fusion at L4-L5-S1 in 1996 with titanium rods, and again in 2001 I had another spinal fusion at L3-L4 with more titanium rods. So now it is 3 years since my last surgery and I am experiencing problems again. Down the side of my right leg was going numb when I lay on my back in bed or lay in a certain position on the couch. Now it goes numb when I stand for longer than 10 minutes, walk any amount of time and in my car at times. I also have a spot on my left thigh about the size of a Softball that has gone numb totally for about 2 months. I also have a pain in my butt cheek whenever I sit. Mostly in the car? Is my pain in my rear end related to nerves in the back? I have also been experiencing my pain levels increasing.
I have seen a doctor and I am now going in for an MRI to try and see what's going on. The doctor is talking about using the Duragesic Patch for round the clock relief. After I had my surgery in 1996, my pain returned and I went for tests to determine what was wrong. The results were that my doctor did not see anything serious enough for surgery and gave me a 60% chance that surgery would help, so I decided at that time to try to maintain a normal life with the pain. At that time I went on the Duragesic Patch for 2-1/2 years when they retested and told me if I did not have surgery soon, I could become paralyzed. So that's why I had the 2001 surgery.
My questions are:
1. Does anyone know if the pain in my rear end is related to the back? (I already know I'm a pain in the butt!)
2.Has anyone else experienced disks going bad like this, one after another? (I was told that once you fix a disk, the next one up is overworked and goes bad?
3. He prescribed me to 5 days of a heavy dose of prednisolone, a steroid. I started on Monday and haven't noticed any difference yet. Anyone else heard of this?

I appreciate any comments very much.