I have had a discogram for T-12, Let me first say I think epidurals and how much pain they cause, depend allot about the individual and the location of the epidurals. I have had epidural in the cervical area and they were a piece of cake, not bad at all, I have had them in the lumbar area, and that was not at all pleasant but tolerable, and I have had them in the Thoracic area, and well lets just say it wasn't good nor pretty! ( as a side not allot of Docs will not give epidural in the thoracic area, as they have said it is tricky and can be dangerous!) My PM does them all and he uses Fluroscopy (spelling) on all his injections, and most of his are a real breeze!
Back to the Discogram, as I mentioned T-12 was not a good area for me, as the disk at T-12 is herniated and torn and the discogram was not comfortable at all, but they did give me pain meds, and something in the IV to relax me! I will say it was worse than some of the epidurals I have had, but not all, and it was not near as bad as the Myelograms I have had in the past! Now those are something that are really different, as the inject dye into your spinal canal, in your lower back and then invert the table so your upside down and the dye runs down toward your head and they take pictures of your spine. in the past they used to use a dye that they would have to remove afterwards, now they use a dye that is absorbed and eliminated rather quickly from your body! The Myelogram is the worst I have ever had! But that is only for me! Everyone is different!
The Diskogram is not super pleasant but not all that bad either! I know I have not been that much help, but Hydrangea you will do just fine, make sure you keep us all posted on how it went for you and how you are doing! We are all here to support you!
Good Luck to You!