Q. If I feel bloated and sick after eating bread and pasta, does this mean I have celiac disease?

A. Celiac disease is a disorder that damages the small intestine and interferes with the absorption of nutrients from foods. In people with this condition, eating food containing the protein gluten triggers the immune system to attack the lining of the small intestine. Gluten is found in wheat, barley and rye.

Symptoms vary from person to person and may include bloating, gas, diarrhea, anemia, bone pain, unintentional weight loss and fatigue. An intense burning, itchy rash that looks like small blisters is also common.

Untreated celiac disease can lead to severe malnutrition. It also increases the risk of intestinal cancers, osteoporosis, seizures and infertility. Because symptoms vary so much, it can easily be misdiagnosed as irritable bowel syndrome, wheat allergy, fibromyalgia or chronic fatigue syndrome. Originally thought to be a rare disorder, experts now think it affects 3 million Americans. Many people with the condition are never diagnosed.

If you suspect you have celiac disease, the first step is to get a blood test that checks for gluten antibodies. Ask for the test if you have anemia, low vitamin D levels, Type 1 diabetes, chronic diarrhea or digestive problems that don't improve with conventional treatments. Those who have a blood relative with the disease should also be tested. If your blood test is positive, the diagnosis should be confirmed with an intestinal biopsy that examines a piece of tissue from your small intestine for abnormalities that are characteristic of this disease.

Fortunately, the damage is reversible if you follow a gluten-free diet, which excludes barley, rye and wheat. Unlike a wheat allergy, which can disappear with age, celiac disease never goes away. For those with celiac disease, a gluten-free diet is a lifelong commitment.

Gluten is found in many foods including breads, baked products, cereals, pastas, canned soups, hot dogs and canned meats, beer, flavored coffees and chocolate bars. It's even in shoyu. Some vitamin supplements also contain gluten. For an extensive list of gluten-containing foods and help learning which ingredients to look for on labels, consult a registered dietitian.

Foods that are naturally gluten-free include plain meats, poultry, fish, eggs, beans, nuts, milk, yogurt, natural cheeses, fruits and vegetables. Luckily, rice is also gluten-free. Gluten-free specialty products are available from health food stores as well as mail-order companies.

Amy Tousman is a registered dietitian and certified diabetes educator with Nutrition Unlimited in Kailua. Hawai'i experts in traditional medicine, naturopathic medicine and diet take turns writing the Prescriptions column. Send your questions to: Prescriptions, Island Life, The Advertiser, P.O. Box 3110, Honolulu, HI 96802; islandlife@honoluluadvertiser.com; or fax 535-8170. This column is not intended to provide medical advice.