I had the joint pain a few years after the Crohn's pains started, but hadn't been diagnosed with Crohn's yet and no one put the two together. I was tested for Lupus, RA, etc. for swelling, painful joints. Only after I started seeing a new GI who has Crohn's and knows more than my last GIs, did he tell me that a lot of Crohn's patients get arthritis also. He really doesn't do much for the arthritis, but has me see the rheumy for that. He's even told me that he has some patients with Crohn's who have no gut symptoms, just arthritis. With me, the arthritis is worse than the Crohn's right now. But, the arthritis meds are also causing stomach pains and ulcers, so it's a struggle finding the right meds.
Crohn's Disease, Acid Reflux/Gastritis, Hashimoto's Thyroiditis, Endometriosis, Arthritis, Depression/Anxiety. Too many meds to list them all. =)