"If you think you are a celiac, the true test is the diet," the doctor advises. "Just try the diet."
Or you might get the opposite response from doctors who have once advised the first way and have had patients fall off the examine table laughing.
"I could never put you on that diet until your diagnosis is confirmed. It's just too hard." That is the learned response of most doctors, or "Let's wait until you have more serious symptoms."
Symptoms like nonhodgekins lymphoma? Esophogeal cancer, Krones, IBS, and 280 different ones. All these symptoms warn that there is something is wrong.
It is hard. From what I've noticed, a person has to be pretty sick--(and somewhat desperate) to agree investigate and try the celiac diet, even for a month. And the results have to be pretty immediate and fantastic to dictate staying on such a strict diet for the rest of your life with no diagnosis.
One nice side-effect is that if you are a celiac and you stick to the diet strictly for any length of time, some people experience a terrible, horrible, no-good, very bad response when they resume a gluten-filled diet. Thereby giving a firm confirmation!