Well I am sorry to hear you are going through CF testing.
The "classic" CF symptoms are failure to thrive, poor weight gain, excessive appetite, respiratory infections, loose/bulky/smelly/greasy stools.
There can also be sinus issues. Some have had all the symptoms & some have had 1. You are fortunate to have a doctor willing to test. We have had members who had all the obvious symptoms, but their diagnosis went undetected for a long time.
May I suggest something to. A sweat test is usually the starting point of testing. Until genetic testing came, sweat tests were the only way to diagnose CF. Since then it seems that the Sweat Test can have many flaws.
It is important that it be done by an Accredited CF Center to avoid any problems. When you are given the results....dont except a "worded result" such as normal, low high or borderline. Get an actual number.
If you are in doubt at any time of the results...demand the genetic testing.
I dont want to scare you, but we have had people with low, borderline or negative sweat tests that got diagnosed through the genetic testing.
If you could share come of your sons symptoms, we might be able to give you some personal feedback as to our thoughts.
I am glad you found us & please ask or come back as often as needed during this whole process no matter what the results!
HUGS