B.J.
Joel, Yes IC can cause lower back pain.My bladder also feels as if it were lined with razor blades and I am peeing ground glass.I suggest you read the book,"You don't have to live with cystitis" by Larrian Gillespie. In she reccomends 1/2 tsp baking soda in 8 oz of water along with the Azo(pyridium),a few hours later take 3-4 tums,this really takes the burn out for awhile.Good luck,I feel for you.