I have AS and crohn's as well. No asthma though. I do get croup like coughs even though I am an adult. I haven't had a cough episode since my diagnoses and actually am very scared that I will get and with my ribs hurting seems like it might be hell. Hope that your ribs and chest infections don't cause more pain.
I find it weird that m rhemy never measure my lung capacity, that sightly unrelated.