Woman kneading bread on a floured table

According to a recent NPD Group survey, more than 30% of Americans try to avoid eating gluten. Despite different opinions on whether gluten is harmful for just those with celiac disease—or for those with other conditions as well—it's become a relevant health topic.

There are different reasons why gluten could be giving you stomach or digestive symptoms, and it's important to go to the doctor to find out the cause of your symptoms. If you think you may be having trouble with wheat or gluten products, keeping gluten in your diet provides the most accurate diagnosis.

Talk to your doctor about gluten intolerance before making any changes to your diet. Going gluten-free before you get tested can prevent accurate diagnosis.

What gluten intolerance means

Gluten intolerance is an umbrella term for any adverse reaction to gluten, a protein that's found in wheat, rye, barley and other grains. Gluten is what gives baked goods their shape and texture. Some kinds of wheat flour like bread flour, have more gluten, and some like cake flour have less—but they all contain gluten.

Most people can tolerate gluten without any issues, but it can cause problems for people with certain health conditions.

Similar symptoms, different conditions

There are three main conditions that can cause gluten intolerance. Although these conditions share many of the same symptoms, they're different in terms of severity and the potential for doing lasting damage to your body. If you suspect one of these conditions, start with your primary care doctor, who can order the tests you need. Use the Find a Doctor tool to get started.

1. Wheat allergy: A food allergy is an abnormal immune response to foods that most of us can eat without issues. People who have a wheat allergy are reactive to wheat but not necessarily to all grains or ingredients containing gluten. A wheat allergy can cause bloating, cramps, nausea, diarrhea, hives and even difficulty breathing. While eating wheat may make you feel sick, it won't usually cause lasting harm and you often outgrow the allergy.

2. Gluten sensitivity: Also known as non-celiac gluten sensitivity (NCGS), this condition is not an immune response. It occurs in the digestive tract and can cause belly pain, bloating, diarrhea and nausea, as well as fatigue and headaches. Gluten sensitivity can probably best be described as a digestive issue.

3. Celiac disease: This inherited autoimmune disease is a chronic condition in which eating gluten causes inflammation that damages the lining of the small intestine. This can prevent absorption of nutrients and lead to health complications like loss of bone density.

Because the symptoms of a wheat allergy, gluten sensitivity and celiac disease—diarrhea, gas, bloating—are so similar to symptoms of other gastrointestinal disorders, celiac is often misdiagnosed as irritable bowel syndrome.

Going against the grains

Lots of people try giving up pasta or cereal and start feeling better. However, the improvement may be due to other reasons, not necessarily because you have a problem with wheat or gluten.

Your best bet is to schedule an appointment with your doctor to get tested for celiac disease. Tests may include blood tests, an endoscopy or a biopsy of your small intestine. Sometimes a colonoscopy is necessary for diagnosis. Because these screenings are diagnostic and not preventive, they won't be covered 100%, but you can use the Cost Estimator to get an idea of how much it'll be. From the Find a Doctor tool, select "Estimate your costs" from the drop-down and search for colonoscopy with biopsy.

If you've been having stomach and digestive issues, see your doctor before starting a gluten-free diet. While your doctor may suggest an elimination diet to find out what you're sensitive to, it's important to go in before making any modifications (this can cause blood tests to be inaccurate). Your doctor can discover the cause of your symptoms, so you can begin the diet and treatment plan that's right for you.