Celiac Disease & Food Intolerances

If you have celiac disease, turn to the experts at UC San Diego Health. Our nationally recognized gastroenterologists and dietitians for the latest diagnosis and treatment strategies.

For those with celiac disease, a gluten-free diet isn't a lifestyle choice -- it's a necessity.

Our dietitians will work with you to develop a comprehensive, personalized nutritional plan to help you restore your health and manage celiac disease symptoms on a daily basis.

Also See Gastroenterology & Digestive Health

What is Celiac Disease?

Celiac disease is a chronic digestive disorder that occurs in genetically susceptible individuals. This multisystem disorder is caused by the body's immune system reacting to proteins in wheat, rye and barley.

The immune reaction damages the lining of the small intestine, causing reduced nutrient absorption. When the intestinal villi in the small intestine are damaged, the body cannot absorb critical vitamins, minerals and calories.

This condition continues as long as these proteins are in the diet.

Facts About Celiac Disease 

  • Celiac disease can develop at any time in a person’s life.
  • Currently, the average age of diagnosis is between ages 40 to 50.
  • Approximately one in 100 people in the U.S. are estimated to have celiac disease, yet only a small percentage of individuals are diagnosed.

Are You at Risk?

The main risk factor is having a family member with celiac disease. The disease can affect anyone, but it tends to be more common in those with existing autoimmune diseases (such as autoimmune liver disease, type 1 diabetes, rheumatoid arthritis, and autoimmune thyroid disease).

Celiac Disease Symptoms

Symptoms of celiac disease can relate to the digestive system or in other parts of the body. From person to person, symptoms can vary a great deal, which can make a definitive diagnosis difficult.

One person may have depression, irritability or fatigue, while another may have diarrhea, constipation, gas, bloating or abdominal pain. These symptoms can also sometimes first appear after an episode of gastroenteritis, severe emotional distress, abdominal surgery, pregnancy or childbirth.

Look for any of the following symptoms:

  • Bloating, gas or abdominal pain
  • Constipation or diarrhea
  • Significant unexplained weight loss
  • Chronic fatigue and weakness
  • Unexplained anemia
  • Premature onset of osteoporosis
  • Itchy skin rash with small blisters
  • Irritability or behavior change
  • Mouth ulcers
  • Tingling or numbness in hands or feet
  • Migraine headaches

Diagnosing Celiac Disease

It's estimated that more than 2 million people nationwide have celiac disease but have not been diagnosed.

While celiac disease primarily affects the gastrointestinal tract, it’s now recognized that the condition can affect other organ systems without showing noticeable gastrointestinal symptoms. This makes diagnosing celiac disease challenging.

Several blood tests are available to screen for celiac disease. The main test used for screening is the tTG-IgA test. Celiac disease blood tests measure for certain antibodies:

  • IgA tissue transglutaminase (tTG) antibody
  • Deamidated gliadin peptide (DGP) antibodies (IgA and IgG)
  • IgA anti-endomysial antibody (used only on occasion)

If the test results are positive, or if the clinical picture suggests celiac disease, an upper endoscopy is performed to get a biopsy from the first part of the small intestine (duodenum).

While a blood test can help detect celiac disease, an endoscopic biopsy is the only way to confirm a definite diagnosis. Up to 10 percent people with celiac disease eating gluten have a "false" normal level of tTG IgA. So if you have pronounced symptoms yet your antibody test results indicate that you do not have celiac disease, an endoscopy and biopsy may be still be performed.

Why You Need A Professional Diagnosis

Celiac disease is not the same as a wheat allergy or gluten sensitivity without intestinal damage (non-celiac gluten sensitivity). The hereditary nature of celiac disease and the risk of nutritional deficiencies, other autoimmune diseases and GI cancers make it important to be properly diagnosed.

Prior to Celiac Disease Diagnosis

It is recommended not to start a gluten-free diet before you are diagnosed. The damage to the small intestine that is caused by gluten in people with celiac disease is reversible, and eliminating gluten from the diet before the biopsy is performed can interfere with obtaining accurate test results. Similarly, the antibody levels will decline once a gluten-free diet is started, making the blood tests less accurate in diagnosing celiac disease.

However, the biopsy can take well over a year or two before it returns to normal, so it is recommended that a biopsy is obtained soon after a patient on a gluten-free diet sees the physician.

Conditions That Can Mimic Celiac Disease

There are other digestive conditions that can cause symptoms from eating wheat and other grains and starches. These conditions are treated differently than celiac disease.

Non-Celiac Gluten Sensitivity

Non-celiac gluten sensitivity (NCGS) is a condition or syndrome that causes digestive symptoms that appear like celiac disease. However, NCGS does not cause intestinal damage or anemia, and the IgA celiac disease antibodies (TTG IgA and DGP IgA) are not typically elevated.

Patients with NCGS are often extremely sensitive to small amounts of gluten. The causes of NCGS are unknown and there are no diagnostic tests that can confirm the diagnosis of this condition.

The absence of the so-called celiac disease susceptibility HLA DQ genes rules out celiac disease and can suggest NCGS in patients with symptoms of celiac disease.

Wheat Starch Intolerance

Another cause of wheat or gluten sensitivity is wheat starch intolerance.

Wheat is made up of proteins (gluten) and carbohydrates (starch) which are found together in baked goods and other wheat products. Some individuals who are intolerant of or sensitive to wheat, like those with irritable bowel syndrome (IBS), are reacting to wheat starch, which can be fermented by bacteria in the intestines (the microbiome). 

If you have IBS and are sensitive to fermentable sugars and starches, you may have symptoms such as:

  • Belly bloating
  • Altered bowel habits
  • Excessive gas
  • Other digestive complaints

Help With Low FODMAP Diet

A low FODMAP diet can be difficult to follow. UC San Diego gastrointestinal experts can help you with FODMAP and other food intolerances.

People with wheat starch intolerance and IBS may alleviate symptoms with a low FODMAP diet. A low FODMAP diet consists of avoiding or limiting intake of certain carbohydrates that can be found in many natural and processed foods:

  • Fructose
  • Oligosaccharides
  • Disaccharides
  • Monosaccharides
  • Polyols

Small Intestinal Bacterial Overgrowth (SIBO)

SIBO is another cause of intolerance of wheat and other starches due to the overgrowth of friendly bacteria in the small intestine.

SIBO can cause several digestive problems including:

  • Food intolerances
  • Diarrhea
  • Altered bowel habits
  • Abdominal pain or discomfort
  • Abdominal bloating
  • Excessive flatulence

In more severe cases, you may experience weight loss, anemia and nutritional deficiencies. The more severe forms of SIBO typically occur in elderly people, after gastrointestinal surgery, and in those who have altered motor function of the digestive tract. 

However, SIBO can occur in individuals who have a seemingly normal digestive tract, as well as those with IBS, celiac disease, and inflammatory bowel diseases (IBD).

Celiac Disease Treatment

Currently, treatment for celiac disease involves following a lifelong gluten-free diet. This means strictly avoiding:

  • Wheat
  • Barley and rye
  • Foods, drinks and medications that contain gluten.

While maintaining a gluten-free diet can be challenging, it is important to restoring your health and improving quality of life.

Our team includes dietitians who provide tailored nutritional counseling to help people with celiac disease and other food sensitivities find foods that are satisfying and healthy. They work closely to provide you with:

  • Recipes
  • Tips for dining out
  • Information on staying gluten-free
  • Identifying hidden sources of gluten 

Our dietitians are also experts in other causes of food intolerances and treatments, including the low FODMAP diet. They will work with you to identify which foods may be the cause of your symptoms and make sure your modified diet is nutritionally balanced.