I've had AS for 25 years and only recently do any changes show up on my xrays. Before that I've had rheumatologist want to take my diagnosis away because I could bend with no problems or because xrays showed no spinal changes. What I have read points to men having faster and more significant fusion in the spine, while women have more peripheral pain. In my case... hips, knees, ribs, ankles... and iritis/uveitis.
Until it is visible on xrays, they are now calling it "non radiographic axial spondyloarthritis".
Hope this helps...

Interesting 30 yrs ago when I was diagnosed it was you have the gene you have the pain you got it.Most Dr's I've seen since have more or less taken same view you have the gene and the pain you have it.Although it did take 7yrs to get diagnosed