I had a discogram before my back fusion, as the insurance company required it as proof that my disk was causing the pain. It was not fun, and it was probably worse than any of the usual spinal injections I had gone through, but mostly it was just because I was scared and did not know what to expect. The worst part was probably laying there with the 3 needles sticking out of my back and just knowing they were there, even though I couldn't see them (and probably just as well that i couldn't) but the only painful part was when they injected stuff into the disks. The ones that were not bad just felt this pressure sensation, and the one that was bad as soon as he injected into that I immediately felt my usual pain and kind of jerked and gasped at that, and then he stopped putting stuff into it. i just remember having to lie there with the needles in my back for a while, since they were doing fluoroscopy scans, etc. The most pain I felt the whole time was at the very end- they had this weird needle in my back that may have been the original guiding one, but it had these little balls every few cm all along it, and when they inserted it i would feel this popping sensation when those balls would go through whatever they went through. At the very end he gave me this massive pain shot in my butt, and then pulled that needle out in one yank and I felt this pop-pop-pop-pop and yelled from the pain, but it was over before I knew it. Afterwards I was not in any more pain than after a spinal injection. And they were very liberal with the pain meds and with the sedation throughout the test, so again, it was not pleasant, i would not want to do it again, but I was much more scared of having it then it really warranted. I have never had a myelogram, but I would imagine one of those would probably be worse. Anyone out there about to have one of these, don't let the pain stories scare you too bad, and just breathe and know you can get through it and it will be over with and then you are smooth sailing from there. And as far as the worst pain I ever felt- that was after my back fusion- no question. After that surgery I totally started doing those 1-10 pain scales differently- I had not had any idea what 10 was until after my fusion. Of course, i was on so much pain medicine before the surgery that there was really no way they could touch my pain, so do not take my story to mean all fusions are that bad.