I don't think many people get a "second opinion" in the traditional sense. Basically, if we are happy that our CF centers are doing a good job, then we stick with them and do what they think is best, even if it's not something we want to hear.
The only time we will change doctors is when we want to permanently change because we are very unhappy with our treatment. (the doctor doesn't care, the doctor is not reachable, the staff is unknowledgable... things like that)
If our doctors advised something like... a feeding tube, for example... well, no one wants to get that. But if we trusted him, we'd follow his advice anyway. We wouldn't rush off to get a 2nd opinion regarding it simply because it's something unpleasant.
Bascially I am asking if you are unhappy with the service your doc is providing, or just something they suggested. Did you think it was wrong or incorrect? etc. Tell us more. <img src="i/expressions/face-icon-small-smile.gif" border="0"> To be honest, if your son is only 9months old he probably (knock on wood) doesn't have too much CF involvement yet, so there isn't too much a doctor could advise anyway - so that might be the reason we seem to get "more advice", we simply have a lot more going on.
Oh and welcome to the site!