I've had swelling/pain in my ankles due to my Crohn's. I, too, am negative for RA.
I recently went to see a Rheumy and she said it's possible my swelling ankles fall in the family of Spondylitis. She said Spondylitis can affect any joint in the body and the pain can often occur because the tendon that is attached to the joint is inflamed causing the swelling and pain of the joint. There's a blood test for ankylosing spondylitis...HLA-B27.
Just thought I'd pass along that information I just recently learned about
Diagnosed in October, 2004 at age 33.
Current Rx's: Colazal (generic), Nexium (generic), Ferrous Sulfate, Librax, One-A-Day multivitamin, Align Probiotic, Omega-3 Fish Oil, Vitamin D, Vitamin A, Calcium-Magnesium-Zinc, Cranberry pills
Secondary conditions: mouth ulcers, joint pain, swelling ankles, extreme fatigue
Previous/occasional Rx's: 20mg Prednisone taper, Flagyl, Levaquin
No surgeries to date