I am not sure exactly what borderline means. I do know they call it the gray area..I would assume that means that they cannot say for sure if it is positive or negative. Was the test done at an accredited cf center? And do you know for sure if they are doing the genetic test that covers even rare mutations (I think it is called the Ambry)? It does sound as if he is having symptoms of cf so it is great that they are doing the genetic testing....I think that is the only way to be really sure about a cf diagnosis. My son never had the sweat test done he only had genetic testing done when he was born (due to meconium ileus). That was how we found out that he had cf. One of my other children did have the sweat test though and his number was 28. You said that your sons stomach hurts all the time....does he have to poop alot and does it look greasy, oily or floats? These are all also signs of malabsorption which is common in cf. I know the thought of cf is scary but if you find out it is cf he will feel much better when put on the proper medications. I am just so sorry you have to wait two months....that is really hard. If you have any more questions I am sure me or someone else on here will have an answer for you. I was so full of questions when my son was first diagnosed. I had no idea what cystic fibrosis was and it was so overwhelming (and still is some days). I have learned alot just from others on this and message boards like it.