“Now medical experts largely agree that there is a condition related to gluten other than celiac. In 2011 a panel of celiac experts convened in Oslo and settled on a medical term for this malady: non-celiac gluten sensitivity.
What they still do not know: how many people have gluten sensitivity, what its long-term effects are, or even how to reliably identify it. Indeed, they do not really know what the illness is.
The definition is less a diagnosis than a description — someone who does not have celiac, but whose health improves on a gluten-free diet and worsens again if gluten is eaten. It could even be more than one illness.”