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The literature I have read says that diagnosis can be made very shortly
after re-introducing gluten to the diet. If Andy has diarrhea that soon
after re-introducing gluten, the GI guy can test for damage to the bowel
then.
        Virginia is two and a half. She has very severe symptoms and
becomes very ill in less than a day after accidently ingesting gluten.
If Andy has so many problems with it, it would be torture for him to
have to go through that for a month!

Sarah Rogers