Oh, it's definitely caused by Crohn's.
I remember being a kid and not wanting to walk anywhere, to just lay there until my legs stopped hurting. And I wasn't on any meds at the time.
It's been so long since I had arthritis, but I'm pretty sure my pains were below the knee.
Diagnosed with typical Crohn's at 16.
Got lucky with Asacol for a year, then even luckier with ten years of relative remission.
Now abscesses and fistulas are having an "atypical" Crohn's party around my junk.
My HMO refused the Remicade and now I could be going on Lialda or sulfa? blah