I too have alot of lower back pain. I'm sure it is related to the crohn's. Try using a heating pad. That seems to help me out a bunch. Gives me some relief without having to pop another pain pill. I wondered if I might not have Fibromyalgia but that's just a guess But seriously give the heating pad a try. My GI's nurse has a sister-in-law with Crohn's and she has the back pain, My nurse told me to try it and I'm glad she did!