I think this would work better for someone who has some symptoms they can use for diagnostic purposes though:
Quit ALL gluten for at least two months (this includes every last, little trace of gluten including shared equipment/cross-contamination, and this means that you likely will need to not eat out at all and prepare all food at home- it's only for 2 months).
Pay attention to the disappearance/improvement of any symptoms during the gluten-free phase. For me, personally, many of my GI symptoms were gone by the end of the second week (14 days in), and most symptoms gone by the end of the first month. Be aware that some people go through gluten withdrawal during this time, which can manifest as ataxia, vertigo, etc (this happened to me, but only lasted about 5 days).
After 2 months have gone by re-introduce gluten in a controlled manner: do not randomly start eating gluten-y junk food, or just any old food at a restaurant, but pick a few things (like regular bread, or cream of wheat cereal) and eat the equivalent of 3-4 servings per day for at least a week. This is so you can be as accurate as possible.
Pay close attention to any symptoms that might happen during the glutening phase: these can be GI issues, skin problems, sleep problems, depression, headaches, anxiety, etc.
If a full week has gone by and there are zero symptoms, then gluten might not be the problem...
This worked great for me because when I started eating gluten again it was very clear (within 3 days) that it was a problem for me... I kept eating it and the symptoms got worse and worse until I went gluten-free again on day 7 or 8. I could see a very clear progression of symptoms during the glutening phase and they all disappeared again after I quit gluten for good.