I can not stand it when I have to deal with Drs who will not listen to me!!!!! I would insist that your son sees a ped. Rhumy. If you need a referal then ask for one and just let them know that it would put your mind at rest if your son was looked into alittle bit further! My son has AS, and it took years for someone to REALLY listen to me and it took about 5 yrs to get a diagnosis, YOU KNOW YOUR SON BEST!!!!!!! Best of luck!