Zoebelle, I have had this issue now for 4.5 years and my neurologist has said it is called Fowler's syndrome. It is caused from surgery most times. Self catheterization is one way to empty your bladder. I have been doing this for over a year now, and the urologist is now doing the urodynics test and I might possibly have to have a pacemaker in my back to stimulate my sacral nerve.
I wish you the best