This didn't happen because you are female, B27-, and he is a non-rheumy. Pardon me for saying so, but this is because that man is an a$$. I have never experienced behavior this disrespectful, outrageous, and ignorant - and I'm also female and B27- with normal looking x-rays and labs!! Plenty of doctors, including rheumatologists, have questioned the diagnosis in my case, but never so rudely. And as others have mentioned - it's not the pain doc's place to confirm/deny the diagnosis but to assist you in managing your pain! This guy is obviously clueless about the AS diagnostic criteria and spondylitis in general.
You asked what you should say in response to this treatment. Honestly, I am pretty assertive but I have to say I'm not sure what I would do/say if a doctor treated me that way (other than never returning, of course.)
On the SIJ injections - if your old pain doc will/can do them and you are willing to travel, it's a good plan to just stick with what was working. If this guy was so emotionally caustic he may be rough with the procedure, too. I had bilateral SIJ steroid injections twice. I did not have sedation (needed to drive myself home afterwards) and had previously had numerous epidural steroid injections also without sedation. For ALL my injections my pain doc did a lot of local numbing. She also proceeded slowly and ensured I was comfortable; she urged me to tell her if it hurt and that she would give more local numbing medicine.
Just my experience FWIW
Oh and the peripheral symptoms are just that - peripheral symptoms. I agree that "peripheral spondylitis" seems like an oxymoron but hey, I didn't go to medical school :p Clearly the disorder encompasses more than the spine and a new name would probably make sense but let's not hold our breath
Welcome to the forums - so sorry for the cause of your introduction, though!!