Alot of what you are describing sounds suspiciously familiar.....Also know that you can always have a false negative sweat test but never a false positive. If the test is positive, it's positive. However, if it's negative, it doesn't necessarily mean negative. I would be sure to have your child tested at a CF Care Center where they know what they are doing and how to read the results accurately. Voracious appetites and low weight gain is a CF symptom.....bulky foul smelling stools that float another symptom...does your child taste salty when you kiss his/her forehead? There are actually so many different symptoms that can be in different children that I can't possibly name them all....every child is different and can show different ones.My daughter presented with a bowel obstruction at two days of age and that's how she was first tentatively diagnosed. We had to wait to have her sweat tested until she was the age of 6 months old and a certain weight. Keep in mind this was 20 years ago and the testing was VERY different than it is now. Not as good and not as quick!Don't let the doctors tell you "not CF" with a borderline sweat test number or because "your child looks healthy". You are going to have to be the best advocate for your child!