Coeliac Disease

Coeliac disease: symptoms, stomach examination, and life without gluten

Are you suffering from constant bloating, abdominal pain, or fatigue? Many Danes live with coeliac disease without knowing it. Here we go through what a stomach examination and gastroscopy involve, and how gluten affects the body in coeliac disease.

In this blog post, we review the current guidelines for work-up and treatment, so you have an overview before you talk to your doctor. The actual pathway is planned individually.

What is coeliac disease?

Coeliac disease is not an allergy, but a chronic autoimmune intestinal disease. When a person with coeliac disease eats gluten (a protein found in wheat, rye, and barley), the immune system reacts by attacking the lining of the small intestine. This leads to damage to the small intestinal villi, making it difficult for the body to absorb essential nutrients such as iron and vitamins.

Typical symptoms:

• Chronic diarrhoea or loose stools.
• Bloating and flatulence.
• Unintentional weight loss and lack of appetite.
• Fatigue and anaemia (iron deficiency).

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The path to diagnosis: The importance of a stomach examination

If you suspect gluten intolerance, it is crucial that you do not stop eating gluten before the examinations are completed. If you remove gluten too early, your intestine may heal, and your tests will then show a false negative result.

Step 1: Blood tests

The first step is a blood test with your GP, measuring a specific antibody, IgA anti-TG2, together with total IgA. Total IgA is measured because selective IgA deficiency makes IgA-based tests falsely negative; in that case IgG-based tests are used instead. The samples must be taken while you are still eating gluten normally, throughout the whole work-up. An antibody result is not a diagnosis in itself: the doctor interprets it alongside symptoms and biopsies. A negative serology does not exclude coeliac disease when clinical suspicion remains high; gastroscopy with duodenal biopsies can still be relevant (Rubio-Tapia et al., ACG Guideline Update 2023). Do not start a gluten-free diet on your own, and do not run your own gluten challenge. The plan is made together with the doctor investigating you.

Step 2: Gastroscopy (Endoscopy)

To confirm the diagnosis in adults, the standard is still a gastroscopy with biopsies. The European ESsCD 2025 guidelines do, however, allow a conditional no-biopsy diagnosis in selected adults with very high antibody levels (IgA anti-TG2 at least 10 times the upper limit of normal). Whether that route applies is a specialist decision, and in Denmark gastroscopy with biopsies remains the usual pathway. This is a specialised stomach examination where a doctor inserts a thin, flexible telescope (endoscope) through the oesophagus to the duodenum.

• What happens? The doctor takes small tissue samples (biopsies) from the small intestine (at least 4 from the duodenum and 1 from the bulb).
• Does it hurt? The examination typically lasts 10-20 minutes. You can receive a local anaesthetic spray in the throat or sedative medication (sedation) to reduce discomfort.
• Special cases for children: ESPGHAN has a biopsy-free pathway that applies to children and adolescents only. It requires all of the following: TGA-IgA at least 10 times the upper limit of normal for the assay, a positive EMA-IgA in a separate, second blood sample, and total IgA assessed. The decision is made by a paediatric gastroenterologist or other relevant specialist, and the family is informed of the benefits and drawbacks of omitting biopsy. The same biopsy-free algorithm cannot be used in IgA deficiency. In adults, biopsy-free diagnosis is not the usual pathway. The child must keep eating gluten during the work-up unless the treating specialist has set out a different plan.

Overview of the diagnostic process

Examination	Purpose	Reference
Blood test	Measurement of tissue transglutaminase antibody (IgA anti-TG2) together with total IgA, taken while you are eating gluten
Gastroscopy	Visual inspection of the mucosa and taking biopsies
Tissue samples (Biopsy)	Detection of flat intestinal villi (villous atrophy) and inflammation
DXA scan	Screening for osteoporosis (brittle bones)

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Treatment plan: Life on a gluten-free diet

Once the diagnosis is made, the documented standard treatment is a lifelong, strict gluten-free diet. The diet is the mainstay of treatment and cannot be replaced by ordinary medical treatment. Rare complicated or refractory courses are handled by a specialist department. When gluten is removed entirely, the lining improves in many people, but the degree of mucosal healing and the symptom response vary, and in adults healing may take longer or remain incomplete (Rubio-Tapia et al., ACG 2023).

The treatment plan includes:

1. Referral to a dietitian: Everyone newly diagnosed should be offered guidance from a clinical dietitian to learn how to compose a healthy, fibre-rich, and nutrient-dense diet without gluten.
2. Check for deficiency states: You must have your levels of iron, vitamin D, B12, and folic acid measured via blood tests. Many need supplements in the beginning. If iron deficiency is found, the choice between oral iron and intravenous iron depends on the cause, the severity, tolerance and response, and is made by the doctor. Iron supplementation never stands alone: the cause of the deficiency must always be investigated.
3. Follow-up: Most people are followed with a check-up after 3-6 months and then once a year to ensure the intestine is healing and that antibody levels are falling.
4. Bone scanning: For adults, a DXA scan is often recommended at the time of diagnosis to check for osteoporosis, which is a known complication of untreated coeliac disease.

What can you eat?

• Naturally gluten-free: Potatoes, rice, maize, millet, buckwheat, quinoa, meat, fish, eggs, fruit, and vegetables.
• Watch out for: Wheat, rye, and barley must be avoided completely. Be aware of hidden gluten in gravy thickeners, breading, beer, and certain types of sweets.
• Oats: Most people with coeliac disease can tolerate oats, as long as they are certified "gluten-free" (to avoid contamination from other cereal varieties).

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Summary: Take your symptoms seriously

Untreated coeliac disease is associated with osteoporosis and an increased fracture risk, and with an increased risk of certain rare lymphoproliferative diseases and of small bowel cancer. It does not imply a generally increased risk of colorectal cancer. If you suspect the disease, contact your doctor and make a plan for your stomach examination. Many people experience improved energy and quality of life on a strict gluten-free diet, but response and healing vary from person to person.

Want to know more? You can always find updated guides at the Danish Coeliac Society or on Sundhed.dk.

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This post is intended for informational purposes and does not replace medical advice. Always contact your doctor regarding persistent symptoms.

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Reference List

1. Danish Society for Gastroenterology and Hepatology (DSGH)

• Title: National treatment guideline: Coeliac disease.
• Focus: Diagnostic criteria for adults, including requirements for gastroscopy and biopsy sampling (4+1 protocol).
• Status: Official clinical guideline for Danish hospitals.

2. Danish Health Authority (SST)

• Title: Coeliac disease and food without gluten - A guide for patients and relatives.
• Focus: Nutritional recommendations, the importance of clinical dietitian guidance, and an overview of naturally gluten-free foods.

3. Lægehåndbogen / Sundhed.dk

• ID: [Coeliac Disease - Overview for health professionals].
• Focus: Pathophysiology (autoimmune reaction), epidemiology in Denmark, and typical clinical presentations such as malabsorption and iron deficiency.
• Diagnostics: Description of the gastroscopy procedure and serological tests (IgA anti-TG2).

4. European Society for Paediatric Gastroenterology Hepatology and Nutrition (ESPGHAN)

• Title: New Guidelines for the Diagnosis of Coeliac Disease.
• Focus: Guidelines specifically for children, where the diagnosis in some cases can be made without biopsy in the presence of very high antibody titres.

6. European Society for the Study of Coeliac Disease (ESsCD), 2025

• Title: 2025 updated guidelines on the diagnosis and management of coeliac disease in adults. Part 1: diagnostic approach. United European Gastroenterol J. 2025. PubMed
• Focus: Adult diagnosis, including a conditional no-biopsy pathway for selected adults with IgA anti-TG2 at least 10 times the upper limit of normal, and at least four duodenal biopsies when biopsy is performed.

5. Danish Coeliac Society

• Title: Life with coeliac disease in Denmark.
• Focus: Practical implementation of a gluten-free diet, including the handling of oats and the risk of cross-contamination.

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