Have you ever eaten gluten? If you've ever eaten a piece of bread, a slice of pizza, or a bowl of cereal, chances are you have.

What's Gluten?

Gluten (say: GLOO-tin) is a protein found in wheat, rye, and barley — grains that are in many everyday foods. Most of us eat food with gluten with no trouble. But for some people, eating gluten can cause a reaction in their bodies. Someone who has this problem has celiac (say: SEE-lee-ak) disease.

After you eat food, it goes to your stomach, which is part of a group of organs that make up your digestive system. An important part of the digestive system is the small intestine, which is lined with villi (say: VIL-eye).

Villi are usually described as microscopic, finger-like projections. They're extremely small — so small you can't see them without a microscope. The villi are important because they absorb nutrients into the body.

For someone with celiac disease, eating gluten — in a piece of bread, for instance — causes an immune system reaction. Your immune system ordinarily keeps you from getting sick, but in someone with celiac disease, the body starts damaging and destroying the villi. Without villi, the body can't absorb vitamins and nutrients from food. Without enough nutrients, a kid's body has a tough time staying healthy and growing properly. Even if the person eats a lot, they still might lose weight and could develop anemia (say: uh-NEE-me-uh) from not absorbing enough iron.

Why Do Kids Get Celiac Disease?

No one is sure why celiac disease happens, but it appears to run in families. Many people who have celiac disease do not know it. If all these people were diagnosed, celiac disease would be more common than type 1 diabetes.

What Are the Signs & Symptoms of Celiac Disease?

Common symptoms of celiac disease are diarrhea, decreased appetite, stomachache and bloating, poor growth, and weight loss. Many kids are diagnosed with it when they're between 6 months and 2 years old, which is when most kids get their first taste of gluten in foods.

For some people, the problems start slowly and the symptoms may be terrible one week and not as bad the next. Because of this, some people aren't diagnosed with celiac disease until they're older. The problem is chronic, which means that although symptoms may come and go, people who have celiac disease will always have it.

Someone with celiac disease may feel tired and could be irritable. Some also have skin rashes and mouth sores. The problem is sometimes mistaken for other digestiveproblems called inflammatory bowel disease (IBD) or lactose intolerance. And in some cases, a kid won't have any symptoms and then will all of a sudden start having problems during a time of stress, such as after an injury.

How Do People Know They Have It?

Someone who has a lot of stomachaches, diarrhea, weight loss, or any of other symptoms of celiac disease should talk to a doctor. It may or may not be celiac disease, but a doctor can help sort this out and will usually order a screening blood test.

If the screening tests show a person might have celiac disease, the next stop usually is to see a gastroenterologist, a doctor who treats digestive problems. This specialist may decide to take a sample of the small intestine to look at under the microscope. This small sample is called a biopsy. If a biopsy is done, the doctor will give some special medicine to help the person stay comfortable during the procedure.

How Is Celiac Disease Treated?

Celiac disease is treated by not eating gluten. This can be hard because gluten is in many foods, but a dietitian can help adjust someone's diet to cut out gluten. It is important not to start a gluten-free diet unless you are truly diagnosed with celiac disease.

Following a gluten-free diet allows the small intestine to heal. But that doesn't mean the person can start eating gluten again. For someone with celiac disease, gluten will always irritate the intestines and, if this happens, the diarrhea, belly pain, and other problems will return.

If you're diagnosed with celiac disease, it can be a challenge to learn which foods contain gluten. You may not be able to remember them all, but you can keep a list with you and ask about menu items at restaurants before digging in. Before you know it, you'll be a pro at knowing which foods are safe and which are not.

Gluten-Free Foods

Here's a quick quiz: Which of these foods contain gluten?

• pizza
• fried chicken
• pasta

If you said all three, you're right! Pizza was the easiest choice because you know the crust is bread. But did you know that battered foods like fried chicken and even some French fries contain gluten? Pasta also contains gluten because it is made from wheat. Luckily, you can make or buy gluten-free pizza crust, make fried chicken with a gluten-free batter, and find gluten-free pasta. In fact, nearly all of the foods we eat can be made gluten free.

Besides foods that contain gluten, you'll need to watch out for foods that may have been contaminated with gluten. This is called "cross-contamination." It means a food doesn't contain gluten as an ingredient but came into contact with gluten-containing foods. This is most likely to happen at home in your own kitchen — for instance, wheat bread crumbs in the toaster, the butter, or jar of peanut butter.

If you have celiac disease you will need your own toaster and you should also have separate spreads and condiments to avoid cross-contamination. Some foods are contaminated during processing, so your mom or dad can help you by finding certified gluten-free foods. For instance, gluten-free oats are now available for people with celiac disease.

The best approach is to read labels. Food labels must say if they're wheat-free products. But a "wheat-free" food isn't necessarily a "gluten-free" one because wheat-free products may have barley and rye (gluten-containing grains) in them.

What Else Should I Know?

Getting used to a gluten-free diet can be hard at first. But over time, you will get to know which foods are OK and which are not, making it easier to find safe meals, snacks, and ingredients.

Remember that you’re not alone with these dietary problems. This website for kids can help too:

• Beyond Celiac