Could this be related to Crohn's???

I have been in remission for approx. 13 years.  Colonoscopy last summer (even though I had no symptoms!) showed minor inflammation so GI has me on Imuran.  When I last flared 13 years ago, it presented as blockages.  In the past 2 months I have had some severe back pain, but today I notice the pain seems to spread around to the abdomen.  My back seems to be especially sore when I sit (especially on a hard chair - rectal pressure?)  I had xrays on my lower back and SI joint which have ruled out AS, but the discomfort is not getting better at all.  Any thoughts - could it be Crohn's related?  Not even sure which doctor I should be seeing!!!

Is there any chance this could be a kidney stone?  As I understand it, the pain starts in the back and moves to the front as the stone leaves the kidney.  Kidney stones are really painful, although I don't know if/why sitting in a hard chair would make a difference.

I have a very similar thing going on. I can tell that pressing on my inner buttock (onto the pelvic floor muscles) increases my discomfort, so rectal pressure may well be a factor. I sit for long periods at my job. GI and I still are in the process of eliminating AS as a cause so I'm not much help to you. Just wanted you to know that you're not alone with your symptom. Hopefully we'll both know more soon.

BTW I have recently finally determined there is a connection between constipation and my low back/butt pain, for what it's worth. I think I've been chronically impacted for so long that I didn't think there was a link. But lately things have been moving better (hooray for BEETS!) and I can tell there is a link. But sometimes I swear I only feel the back pain so I think it must be that which is causing my LRQ pain. Of course the two are related since that part of the spine apparently controls the abdominal organs. No wonder the source of some pain is so hard to determine. Good luck to you!

That's interesting about the B12 neuropathy. I didn't know that could be a cause as well.