Yes, I Am A 64 Year Old Female. I Have

Yes, I am a 64 year old female. I have been experiencing sharp gnawing pain in my lower back extending to my hips on either side and 1/2 way down both thighs. The pain comes and goes. Sometimes it will last for days and then I may have relief for a time. It is especially painful going up or down stairs. I also noticed that for some odd reason it seems to be a bit relieved when I have a bowel movement. What might this be?