... effects of gabapentin. Happy to report after being on them for about a month now, I am doing much better. I have found out the pain I am having is due to my Sacroiliac on my left side slipping. I am having one more injection {required by insurance} for a total of 3. Then I am having IFUSE done to hold it in place. But I was told by my surgeon that I need a CT scan of my pelvic now, before insurance will pay. I have searched everywhere and I can't find out why this would be needed. The nurse could not tell me either. I have had a hysterectomy years ago. So I don't get it. Does anyone know why? We really don't need another bill at this point.