My 18 year old son has had AS symptoms, on and off, since he was 14. Debilitating pain that has affected his life greatly. Both of my brothers have been diagnosed with AS. So, when my son started having hip pain and joint stiffness I unfortunately took for granted that his diagnosis would come easily. There are days that his pain is so bad he needs help to get up out of a chair, he can’t tie his boots or take them off at the end of a day. He really doesn’t remember what it’s like not to be in pain anymore. His Rheumatologist hasn’t been able to diagnosis him with anything according to his blood work and x-rays. They have contributed all of his pain to low vitamin D levels. My son has been on a vitamin D supplement for 6 months with absolutely no improvement. I am taking him to see a new Rheumatologist in a few weeks and I’m wondering what tests I should be asking for? Would an MRI be a better test than the x-ray that they gave him? I’m at a loss for how to help him or what to ask for exactly when we see the doctor.