I think I just found something that fits my symptoms more than my diagnosis of AS. I literally stumbled upon it an hour ago and decided to check out these forms to ask about this condition and saw your post. It sounds like you might fit this as well. It’s called Non-Radiographic Axial Spondyloarthritis.
Basically patients with NRAS present outward symptoms consistent with AS, but they show no signs of AS in their X-rays and MRIs (which is my case as well). I’m currently looking for more info, but can’t find much. Seems like NRAS is a pretty recent thing that medical journals and studies have only just begun looking into. For instance I don’t know if it it is just an early form of AS or something a little bit different than AS. I also can’t find anything on patients who (like me) test postitive for HLA B27 and weather or not being HLA B27 positive has the same correlation with NRAS as it does with AS, however what I have found seems to say that the same medications and treatments for AS also help patients with NRAS.
You might want to bring this up with a Rheumatologist, though I don’t know if it would be better to go back to the one of the doctors you’ve already seen, or seek out a third opinion, perhaps with someone who has experience with patients with AS and patients with NRAS.https://www.ncbi.nlm.nih.gov/pubmed/26897981http://www.rheumatologynetwork.com/...l-spondyloarthritis-treatment-guidelines