<<Disclaimer: Verify this information before applying it to your situation.>> Hello to all again, I failed to mention in my previous post that Grant had been GF for a short time before testing and greatly improved. We put him back on gluten for about two weeks prior to the testing. The doctor said that would be enough time. But I just read on the enabling website that it usually takes four weeks for a challenge and you need to wait for the symptoms to return before doing the test. At the time of the test, my son's symptoms had not returned; diarrhea being the symptom. This is such a regimented diet that I would like to know for sure if he has Celiac or not before requiring him to be GF for the next 70 years as he is only 2 now. Also, I have heard that it wreaks havoc on a Celiac's body if you go GF then challenge then go GF then challenge then go GF then challenge just for the sake of testing. Is this true? Could it do irreversable damage? We have such a dilemma. By the way, his labwork was sent to LabCorp in Burlington, NC. I called and they have already disposed of the specimen. Melinda