Have you gone gluten-free because you're convinced that the protein is giving you gastrointestinal (GI) issues? If you haven't talked to a doc, that might be a mistake. A new study shows that many people who adopt a gluten-free diet haven't been appropriately tested for celiac disease.

Researchers from Eastern Health Clinical School at Monash University and Alfred Hospital in Melbourne, Australia, recruited 144 people who said they suffered from non-celiac gluten sensitivity (NCGS). Turns out, 44 percent of participants had initiated a gluten-free diet without any medical supervision--and 69 percent of them hadn't gotten the necessary testing for celiac disease. (It's important to get tested by a doc before you start a gluten-free routine because it's hard to tell if the protein is a problem for you after it's already been eliminated from your system.)

MORE: 9 Things You Should Never Say to Someone Who Eats Gluten-Free

Another interesting fact from the study: Seventy-two percent of participants didn't even end up meeting the criteria for NCGS. While 62 percent of this group fell into the category because researchers couldn't rule out celiac disease for them, 24 percent continued to have gastrointestinal issues despite following a gluten-free diet (irritable bowl syndrome or a wheat allergy can both cause similar symptoms).

The bottom line: You shouldn't be self-diagnosing a gluten issue. If you think you might have one, ask about the test for celiac disease so you don't have complications down the road. How do you know if you should book an appointment? Dr. Gina Sam, director of the Mount Sinai Gastrointestinal Motility Center at The Mount Sinai Hospital, says these symptoms are telltale signs:

You have chronic GI symptoms. These include severe or recurrent diarrhea, weight loss, and abdominal distension or bloating.

You're deficient in iron, folate, or vitamin B12. Since untreated celiac disease damages certain parts of the intestine where these vitamins are absorbed, deficiencies can be a tip-off that you have an issue.

You have family history. Even if you're asymptomatic, first-degree relatives of patients with a confirmed diagnosis of celiac disease should definitely get tested.

MORE: Watch People Who Say they Eat a Gluten-Free Diet Try to Explain What Gluten Is