Diarrhea. Abdominal pain. Bloating. These annoying symptoms can occur in many gastrointestinal problems that teenagers experience. On social media, on the bleachers at school sports events, at doctors’ appointments, it seems like everywhere people are talking about gluten.

So what exactly is gluten?

Gluten is a group of proteins commonly found in wheat, barley, oats, and rye. It affects the dough quality of breads and is added to processed foods to improve texture, moisture, and flavor.

When should a teenager go gluten-free? When they are diagnosed with a problem caused by gluten. Celiac disease, wheat allergy, and gluten intolerance involve gluten but are not one and the same.

Celiac disease is an autoimmune disease where gluten triggers the body’s immune system, which normally makes antibodies to fight off harmful invaders like viruses or bacteria, to make antibodies against itself. These “autoantibodies” damage villi, finger-like projections lining the small intestine. Damaged villi can’t absorb important vitamins and minerals that a teenager needs to grow. The cause of celiac disease is unknown, but it may run in families. It also can occur with other disorders, such as Down syndrome, diabetes, and autoimmune thyroid disorders. Gastrointestinal (GI) symptoms include diarrhea, constipation, abdominal pain, and bloating. Other symptoms include weight loss, fatigue, headaches, rashes, anemia, osteoporosis (bone thinning), and joint pain.

The diagnosis of celiac disease starts with a blood test to look for autoantibodies. A gastroenterologist may biopsy the small intestine to confirm the diagnosis. Genetic testing can also be performed. Treatment is completely eliminating gluten from the diet, allowing the intestine to heal and symptoms to improve.

In wheat allergy, the body’s immune system mistakes gluten, or other proteins found in wheat, as something to fight off by making antibodies. When exposed to wheat, these antibodies rev up, causing nasal congestion, itchy watery eyes, hives, or GI symptoms like those of celiac disease. For some people, wheat allergy may cause a life-threatening reaction called anaphylaxis:

• Throat and tongue swelling

• Trouble swallowing

• Difficulty breathing

Wheat allergy is more common in children and many children seem to “outgrow” it.

Diagnosing wheat allergy starts with keeping a food diary to determine the relationship between diet and symptoms. An allergist may do skin testing: injecting drops of wheat proteins under the skin and monitoring for reactions. Blood tests look for specific antibodies. An elimination diet may be recommended where certain foods are avoided then gradually added back to see if symptoms return. An allergist may challenge the patient in the office by having them consume wheat and monitoring for symptoms. Don’t try this one at home!

The treatment of wheat allergy is avoiding wheat. Gluten-free foods are free of wheat (but wheat-free foods might not be free of gluten!). If an allergic person is exposed to wheat, antihistamines may relieve minor symptoms. For more serious reactions such as anaphylaxis, an epinephrine auto-injector is used.

Gluten intolerance, also known as Non-Celiac Gluten Sensitivity (NCGS), is not an autoimmune disorder or an allergic response. As with celiac disease and wheat allergy, GI symptoms occur after consuming gluten. NCGS can also cause fatigue, headaches, and “brain fogginess.” The immune system is thought to play a role, but the process is still not understood. NCGS is diagnosed after excluding celiac disease and wheat allergy and if symptoms improve with elimination of gluten from the diet. The treatment of NCGS is a gluten-free diet.

Our advice to parents: Going gluten-free is no piece of cake. It requires paying careful attention to everything that is consumed. Gluten is found in many foods, including some that may surprise you: soy sauce, flavored potato chips, salad dressing, and deli meats. Fortunately, there are more and more resources available for those in need. Online resources, such as one you’ll find on the Mayo Clinic website, can help identify foods that are gluten-free. Though there are plenty of gluten-free products on grocery store shelves, it is important to teach your teenager how to read food labels, and how to ask confidently about what’s in foods when eating out.

Having to follow a special diet and having distressing GI symptoms can be extremely isolating for a teenager who just wants to be “normal” and fit in. We recommend keeping close tabs on the emotional health of your teenager. Trust us: the more you talk, the more they’ll talk.

Some helpful support groups:

For celiac disease: https://nationalceliac.org/celiac-disease-support-groups/

For wheat allergy: https://www.foodallergy.org/living-food-allergies/join-community/find-support-group

For NCGS: https://gluten.org/community/support-groups/

Srushti Raja is a pediatric resident and Rima Himelstein is an adolescent medical physician and Nemours Children’s Hospital, Delaware.