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Column originally published Oct 23, 2007

Celiac Disease Needs Blood Test And May Be Endoscopy

Question: We have a debate in our family. A few months ago, my husband was diagnosed with celiac disease after a long bout of diarrhea. He is doing a lot better now after he started the gluten-free diet. There are many relatives on his side of the family who have had cancer of the intestines, although none of them were ever diagnosed with celiac disease. We want our two teenage sons to be tested, but they refuse because they don’t want to go on this diet. Right now they are completely healthy. We would appreciate some advice whether we should insist on them getting tested.


You have a rather difficult dilemma. I can understand why your sons refuse to be tested. However, with all the information that is available to us, they would benefit from the highly reliable tests to find out whether they have celiac disease or not. Let me explain to you in more detail here.

Celiac disease is an allergic condition of the small intestines. Like many other allergic conditions, it is related to our genes. There are a number of genetic markers being identified, although the actual genes have not been found yet. It affects all ethnic groups, although those who came from northern Europe have the highest chance of developing celiac disease. In Canada, it is estimated that one in 133 people will develop celiac disease some time in their life.

The substance that triggers allergy in the small intestines is a protein called gluten. It is found in wheat, rye, triticale (a hybrid grain produced by crossing wheat and rye), as well as barley. When these foods are consumed over a period of time, the gluten would stimulate the immune cells and these in turn would cause extensive damage to the inner lining of the small intestines where food is being digested and absorbed. With this damage, not only food cannot be properly digested, it cannot be effectively absorbed also.

For many years, celiac disease was only diagnosed in young children, usually under one year of age, after they have been fed with foods that contain gluten. Because they cannot digest and absorb food properly when their intestines are damaged, many of them have diarrhea, with undigested food present in the stool. Their abdomen becomes distended, and they are often very irritable. Blood tests would show that they are lacking nutrition, including vitamins, iron, and calcium.

It was observed that babies who are being breastfed are less likely to develop celiac disease even though this illness is in their family. It is unclear whether breast feeding actually prevents celiac disease, or it just delays the onset of the illness.

Adults who develop celiac disease often have bloating sensation in their abdomen and diarrhea. Many have these symptoms for years before seeking medical attention. Some will complain of being depressed and lack of energy. Blood tests often show that they have low iron level and anemia. Some even have evidence of osteoporosis because they cannot absorb calcium.

We still don’t know why some children develop symptoms and getting diagnosed in infancy, while others are healthy until much later. The availability of screening tests in recent years is likely the cause of a great surge in the number of adults getting diagnosed with celiac disease, even though they may have little or no symptom.

Although blood tests have become much more accurate, definitive diagnosis of celiac disease still rests with endoscopy and biopsy. A tube-like instrument, called an endoscope, is passed into the stomach and small intestines. Small pieces of tissue are then taken to be examined under the microscope. This is regarded as the gold standard in diagnosing celiac disease, and should be done especially in those who have no symptoms, before advising a person to go on the gluten-free diet for the rest of his or her life.

The question that is often raised, especially by teenagers, is why should they go on the diet if they are still healthy. The reason is because if they have celiac disease, continuous exposure to gluten will continue the damage in their intestines. Over time, it will lead to nutritional issues because the intestines cannot absorb nutrients properly. Osteoporosis is a known complication of celiac disease.

Those with celiac disease also have a higher chance of developing cancer of the esophagus, stomach, and intestines. However, we don’t know whether these cancers are caused by celiac disease.

The only treatment available at the present time for celiac disease is avoiding foods that contain gluten. Many processed foods and medicine have gluten added, therefore, it is most important to read all the ingredients on the label. Oat used to be a grain that people with celiac disease have to avoid. More recent research shows that most can consume 50-70 grams of oat a day without problem. The greater difficulty is that oat is often contaminated with wheat and other grains that contain gluten when it is being grown and harvested. The Canadian Celiac Association is developing a certification standard for pure and uncontaminated oats and oat products, which will be helpful for you when you shop.

Because your husband has celiac disease, both of your boys may carry the genes predisposing them to the same illness. We don’t know how the genes for this disease is being inherited as yet. Therefore, they can have the disease without any symptom. They should have blood tests first, if they are negative, then they likely don’t have this condition. However, if these are positive, then they need to undergo endoscopy and biopsy to confirm the diagnosis. If they do have celiac disease, it is important for them to start the gluten-free diet even though they have no symptom. By staying on the gluten-free diet, their intestines will stay healthy, and hopefully they will stay healthy as well.