What is celiac disease and what is gluten?
Celiac disease is a genetic autoimmune disorder. This means that it is a condition that is passed down in families where the immune system attacks a healthy part of the body by mistake. In celiac disease, the storage protein (known as prolamins) found in certain grains triggers the body to cause damage to the small intestine. These prolamins are specifically known as gliadin when found in wheat, secalin in rye, and hordein in barley. All forms of these grains must be avoided. The only treatment for celiac disease is to follow a gluten-free diet for life. 1 Visit Simple Start to the Gluten-Free Diet to learn which grains to choose and which to avoid.

Who gets it?
Celiac disease may affect as many as 1 in 133 Americans but an accurate number is unknown because many cases remain undiagnosed and underdiagnosed. 2 It is most common in people with North American or European descent, but is also found in people from the Middle East, North Africa, Turkey, India 3 ,4, 5, 6 and around the world.

When does it develop?
Celiac disease tends to run in families because people who have celiac disease inherited the genes. These genes can be "activated" at any time, or not at all, during a person's life because of certain environmental factors. 1

What happens when a person eats gluten?
If someone has celiac disease, eating gluten results in the immune system damaging the villi which line the small intestine. 1 These villi absorb nutrients from food and move them into the bloodstream where they can be used by the body. Without enough healthy villi, a person will not get the nutrients he/she needs. 7

What are the most common symptoms of celiac disease? 8

The following common symptoms USUALLY respond to the gluten-free diet.

  • Diarrhea
  • Abdominal bloating
  • Abdominal discomfort/pain
  • Excess gas
  • Constipation
  • Fatty stools
  • Fecal incontinence (soiling (stool) accidents)
  • Nutritional deficiencies, such as iron, calcium, vitamin D, B vitamins, vitamins A, E, and K, zinc and other minerals, etc.

The following common symptoms SOMETIMES respond to the gluten-free diet. 5

The following commonly associated conditions ARE NOT expected to respond to the gluten-free diet. 8

To learn more about atypical (not typical) symptoms, please visit Level 3.

What is the difference between celiac disease, non-celiac gluten sensitivity, and a wheat or gluten allergy?

Celiac disease is a genetic, autoimmune disease triggered by the ingestion of gluten in which the individual makes antibodies called auto-antibodies that attack and damage the lining of the small intestine.

Non-celiac gluten sensitivity (NCGS) is a recently described condition with symptoms similar to those in celiac disease. Unlike celiac disease, there is no genetic susceptibility to NCGS, there are no auto-antibodies to damage the lining of the small intestine, and there is no association with other autoimmune diseases. 9,10 In NCGS, the small intestine is normal. 11 Patients with NCGS have symptoms that improve or even disappear after withdrawing gluten from their diet. 12 As a result, many patients with NCGS will experiment on their own with a gluten-free diet. Currently, there is no evidence to suggest that people with NCGS must follow the gluten-free diet as strictly as those with celiac disease. Until such data is available, people with NCGS should do whatever they feel provides them with the best overall quality of life.

Postings on Non-celiac gluten sensitivity:

A gluten or wheat allergy involves an adverse immune response to the gluten or other wheat (cereal) proteins that leads to symptoms such as swelling around the mouth, hives, sneezing and stomach discomfort. Damage to the small intestine, however, is mild and usually short-lived. 13 Some symptoms are the same as seen with celiac disease, but an allergy can, at times, result in immediate and life-threatening symptoms.

When is the time to visit a gastroenterologist?

It is appropriate to test for celiac disease in the following situations: 8

  • Chronic or recurrent gastrointestinal symptoms, including
    • Symptoms suggesting irritable bowel syndrome
    • Symptoms suggesting lactose intolerance that do not resolve on a lactose-free diet
  • Unexplained iron deficiency anemia
  • Unexplained, marked vitamin D deficiency
  • Unexplained osteoporosis
  • Unexplained vitamin B12 deficiency
  • Unexplained weight loss (or failure to gain weight in children)

Unexplained infertility. 14

  • Always speak to your doctor if you have any symptoms that concern you.


  • The symptoms listed above are not unique to celiac disease and can occur with other disorders and diseases.
  • If you or your doctor recognize your symptoms in the list above (or in Level 2), consider getting tested for celiac disease.
  • If you suspect celiac disease, do not start a gluten-free diet on your own until you have consulted with a gastroenterologist and have been tested.
  • Early diagnosis and effective treatment of celiac disease greatly improves your health outcomes and reduces the risks of complications from untreated disease.


  1. Green PH, Cellier C. Celiac Disease. N Eng J Med. 2007;357(17):1731-43.
  2. Aybar A. A Global Disease: The Iceberg Dilemma. In Real Life with Celiac Disease: Troubleshooting and Thriving Gluten-Free . Eds. Dennis M, Leffler D. AGA Press. Bethesda, MD, 2010.
  3. Beth Israel Deaconess Medical Center Celiac Center. General FAQ about Celiac Disease.
    Accessed August 11, 2011.
  4. Makharia GK, Verma AK, Armachand R et al. Prevalence of celiac disease in the northern part of India: a community-based study. J Gastroenterol Hepatol. 2011;26(5):894-900.
  5. Dalgic B, Sari S, Bastruk B et al. Prevalence of celiac disease in healthy Turkish school children. Am J Gastroenterol. 2011;106(8):1512-7.
  6. Israeli E, Hershcovic T, Grotto I et al. Prevalence of celiac disease in an adult Jewish population in Israsel. Isr Med Assoc J. 2010;12(5):266-9.
  7. National Institutes of Health Publication No. 08-4269 September 2008. .Accessed August 11, 2011.
  8. Kelly C. Common and Uncommon Presentations of Celiac Disease. In Real Life with Celiac Disease: Troubleshooting and Thriving Gluten-Free . Eds. Dennis M, Leffler D. AGA Press. Bethesda, MD, 2010.
  9. Cooper Bt, Holmes GK, Ferguson R et al. Gluten-sensitive diarrhea without evidence of celiac disease. Gastroenterology. 1981;81:192-194.
  10. Newnham ED. Does gluten cause gastrointestinal symptoms in subjects without coeliac disease? J Gastroenterol Hepatol. 2011;26:132-34.
  11. Leffler D. Gluten Intolerance: You Mean I Don't Have Celiac Disease? In Real Life with Celiac Disease: Troubleshooting and Thriving Gluten-Free . Eds. Dennis M, Leffler D. AGA Press. Bethesda, MD, 2010.
  12. Biesiekierski JR, Newnham ED, Irving PM et al. Gluten causes gastrointestinal symptoms in subjects without celiac disease: a double-blinded randomized placebo-controlled trial. Am J Gastroenterol. 2010; 106(3):508-14.
  13. Up to Date. . Accessed October 9, 2011.
  14. University of Chicago Celiac Disease Center Impact Newsletters 2008; 8(1). Accessed August 11, 2011.

    Revision Date: 10-31-12
    Authors: Melinda Dennis, MS, RD, LDN and Annie Peer
    Editors: Suzanne Simpson, RD and Rupa Mukherjee, MD

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