Coeliac disease overview

The symptoms of coeliac disease are different for everyone. They can be similar to those of several other conditions, such as irritable bowel syndrome, which can complicate diagnosis.

Symptoms in adults

In adults, common symptoms include:

• Diarrhoea (hamuti, runny poo), which may begin at any age and is often present for years before a diagnosis. It may first appear after other illnesses, such as a tummy bug (gastroenteritis), or after significant health events such as surgery, pregnancy or childbirth.
• Tiredness, weakness and lack of energy.
• Weight loss.
• Constipation (some people are more likely to experience constipation – poo that's hard to pass – rather than diarrhoea).
• Flatulence (wind, gas) and abdominal (tummy) tightness.
• Cramping and bloating.
• Nausea (feeling sick) and vomiting (being sick).

Anaemia is also more common in people with coeliac disease, particularly anaemia due to iron or folic acid deficiency. Either the anaemia won't  respond to treatment or it will come back after treatment until the underlying cause (eg, coeliac disease) is identified and treated.

Less commonly, as an adult you may experience:

• Easy bruising of your skin.
• Ulcerations and/or swelling of your mouth and tongue.
• Miscarriages and infertility.
• Low blood calcium levels with muscle spasms.
• Vitamin B12, A, D, E and K deficiencies.
• Skin rashes such as dermatitis herpetiformis (see below).
• Altered mental alertness.
• Bone and joint pains.

Symptoms in children

In children, symptoms don't appear until gluten-containing foods are introduced into their diet. It's also possible for symptoms to appear later. See our page on coeliac disease in children.

Dermatitis herpetiformis

Dermatitis herpetiformis (also known as DH or Duhring’s disease) is a chronic, intensely itchy, blistering skin condition which is also caused by an immune reaction to eating gluten. It may or may not be associated with other coeliac disease symptoms but is linked to coeliac disease. The name herpetiformis comes from the tendency for blisters to appear in clusters, resembling herpes simplex. However, dermatitis herpetiformis is not due to this viral infection. Everyone with DH also has coeliac disease. Read more about dermatitis herpetiformis.(external link)

Having coeliac disease is different to being gluten-intolerant

Some people who don't have coeliac disease also avoid gluten in their diet. This is because they have found that foods containing gluten make them feel generally unwell, possibly with bloating and tummy pain. They are ‘gluten intolerant’ but they don't develop inflammation in their gut. Read more about gluten intolerance.

(Patient Info, UK, 2018)

Coeliac disease is caused by an abnormal reaction by your immune system to the protein gluten, but why this sensitivity develops isn't well understood.

• Your immune system mistakes gluten as a threat to the body and, in an attempt to protect your body from the threat, it creates special gluten-fighting antibodies to fight it.
• In your gut, these antibodies cause inflammation and flattening of tiny, finger-like projections called villi, which line the inside of your small intestine (also known as small bowel).
• The villi are responsible for absorbing nutrients and minerals from food.
• Damage of the villi can lead to nutritional deficiencies – low levels of iron, folic acid and calcium.
  
  

Image credit: Depositphotos

If it's not diagnosed, the condition can cause long-term poor health (see below) so it's important to see your healthcare provider if you think you may have the condition. 

Coeliac disease can develop at any stage in life, from infancy to old age. It occurs in family groups and has a strong genetic tendency.

• About 10% (1 in every 10) of all first-degree relatives (parents, brothers, sisters or children) of people with coeliac disease also have the condition.
• If one identical twin is affected, the other twin is almost certain to be affected.

Coeliac disease can develop in babies, while older children or adults who haven't previously had problems may also become gluten-sensitive at some point in their lives and develop coeliac disease. It's not known why the immune system of some people becomes sensitive to gluten. There is no evidence that stress or the use of antibiotics triggers coeliac disease.

Risk factors

Risk factors for coeliac disease may include:

• dermatitis herpetiformis
• thyroid disease
• type1 diabetes
• immunoglobin A (IgA) deficiency
• Down syndrome
• Turner syndrome[CB1] [CB2] 
• a family history of coeliac disease.

If coeliac disease is suspected, a blood test will be done to look for certain antibodies that are present in the blood of a person with coeliac disease. If the results are positive, more tests may be needed. You may be referred to a specialist who may arrange for you to have a gastroscopy and for a biopsy to be taken. 

A gastroscopy is a way to look inside your stomach and the upper part of your gut with a thin flexible tube (endoscope). A biopsy is a procedure in which a small sample of tissue is taken. For coeliac disease testing, the biopsy is taken from the inside lining of the beginning of your gut (duodenum) during the gastroscopy. The sample is looked at with a microscope to see if the typical changes of coeliac disease are present.

Other tests may also be done to find out if poor absorption of food and nutrients has affected you eg, blood tests for anaemia or a special bone scan.

The gold standard for diagnosis is:

• a positive blood test, and
• finding small bowel abnormalities if duodenal biopsies are performed while you're still consuming gluten.

Read more about testing for coeliac disease(external link).

Important: You must continue to consume gluten while you're being tested for coeliac disease. Taking gluten out of your diet before a diagnosis may make blood tests and biopsies less accurate. Feeling better on a gluten free diet isn't enough to confirm the diagnosis of coeliac disease.

There is no known cure for coeliac disease. A strict gluten free diet is the only effective treatment if you have been diagnosed with coeliac disease. There are no medicines to treat it, but medicines may be needed to treat comorbidities, such as iron deficiency. 

• A gluten-free diet means a lifelong, no-exceptions diet, leaving out all foods containing wheat, rye, barley, triticale and oats. It is essential that you avoid the risk of cross-contamination in food storage and preparation.
• Oats can cause a reaction in some people with the condition, so they're not safe to include in a gluten free diet even if they are labelled as ‘gluten free oats’. Read more about Coeliac NZ's position on oats(external link). 
• Children and younger people recover quite quickly after starting a gluten-free diet (usually within 6 months), but older people may take longer to recover.
• At the start of treatment, supplements such as iron, folic acid and some vitamins may be needed to correct any nutrient deficiencies. Your healthcare provider can advise you on this.  
• It's not unusual for people to experience lactose intolerance when they're first diagnosed with coeliac disease. Reducing lactose-containing products may help, and this is often a short-term issue that improves over time. Always consult your healthcare provider for personalised advice. Read more about lactose intolerance.

If you have coeliac disease and eat gluten, it will continue to trigger your immune system and damage your gut .

You should get advice from a dietitian to find out which foods are suitable. 

Patient Registry

Coeliac NZ has teamed up with the Celiac Disease Foundation to create the first patient registry database capturing the experiences of New Zealanders living with coeliac disease. This registry gives participants the chance to contribute to a national database and be part of the journey toward a cure. Find out more and sign up for free(external link).

Apps reviewed by Healthify

You may find it useful to look at some digestive health apps.

If you have untreated coeliac disease you are at greater risk of developing long-term health conditions such as:

• osteoporosis (low bone density and increased risk of fractures due to reduced dietary calcium absorption)
• iron deficiency anaemia
• infertility
• miscarriage
• depression
• dental enamel defects
• increased chance of cancers of your oesophagus and gastrointestinal (gut) tract.

Read more about the conditions associated with coeliac disease.(external link)

The increased risk of these conditions usually reduces if you follow a strict gluten-free diet.

Talk to your healthcare provider if you have further concerns or additional symptoms.

For more information, resources and support, become a member of Coeliac New Zealand.(external link) Coeliac New Zealand are the voice for coeliac disease in Aotearoa New Zealand. They provide support and advocacy for everyone with coeliac disease and for those needing a medically warranted gluten-free diet. As a member you'll join a supportive community offering resources, shared experiences and guidance through living with coeliac disease. Your subscriptions also help provide the resources needed to work with health professionals, gluten free manufacturers, and researchers to advocate and raise awareness of coeliac disease in Aotearoa New Zealand.

As a member you will receive:

• A welcome pack containing information on the condition, the gluten free diet, where to shop, recipes and helpful advice to make the change from gluten to gluten-free as easy as possible. 
• A dedicated Coeliac Link magazine with informative articles and contributions from experts and ambassadors as well as lived experience stories from members. It's published twice a year.
• Regular messaging to members with opportunities to try new products before they hit the shelves..
• An informative and engaging website.
• Access to a first class gluten-free food safety training certificate including an advanced masterclass.
• Health promotion programmes and toolkits.
• Local gatherings run by volunteers in the community.
• A wellbeing journal for inspiration, tips and ideas to support your journey. Resources to buy. 

You may eligible for financial support with your health-related costs. Read more about financial support(external link). 

Remember the change to a gluten free diet after being diagnosed with coeliac disease can have a significant positive impact on your wellbeing.

Video: Gluten free for life

(Coeliac NZ, 2018)

Video: Living with coeliac disease – the less spoken about topics

(Coeliac NZ, 2022)

Video: Don’t pass the bread

This video focuses on life after diagnosis, when drastic lifestyle changes are required both within and outside of the home. From afar, the requirement seems simple – don't eat gluten nor traces of gluten. However, in a world where gluten is in sauces, meats, and make-up, where simple family gatherings are rife with gluten contamination, and when sharing a bag of chips can lead to days of sickness, the disease can affect your social and mental health. 

(Coeliac New Zealand, 2021)