Hi, Maggie:
We all once hoped that we would find a doctor who would help us, but such hopes were usually dashed after a few visits and then no change (in the proper direction) for many years.
Despite RESULTS to the contrary, so many of our group are still waiting for the magic pill or treatment instead of doing our radical dietary change and taking the supplements that help us heal properly.
I can tell you that being dehydrated will not cause an AS flare, but AS will often lead to costochondritis.
Carol Sinclair was interviewed on Australia Overnights, and her book should be available there (unlike here in US). I hope that you will check it out, as well as join us on the
NSD Forum.
Best to You, whatever you decide,
John