Health condition · Clinically reviewed
Coeliac disease, autoimmune gluten intolerance, correctly diagnosed.
A lifelong autoimmune reaction to gluten. Diagnosis needs anti-tTG antibodies WHILE eating gluten — plus confirmatory endoscopic biopsy in adults. Lifelong gluten-free is the treatment.
Why trust this guide
- 01
Clinically reviewed
Written by our editorial team and reviewed by a registered UK clinician before publication.
- 02
Sourced from guidance
Checked against NICE, BSG and Coeliac UK sources you can see at the end.
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Current for 2026
Reflects current UK guidance on coeliac serology, biopsy and gluten-free management.
Key facts
Coeliac disease at a glance.
The essentials, in plain English — what it is, how it is diagnosed, and how it is treated in the UK today.
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What it is
An autoimmune enteropathy triggered by gluten — not an allergy, not an intolerance.
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How common
Around 1 in 100 UK adults; many remain undiagnosed for years.
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Test on gluten
You must be eating gluten regularly for at least 6 weeks before testing — otherwise results are unreliable.
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First-line test
Anti-tTG IgA antibodies with total IgA — the correct starting point in adults and children.
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Confirmation
Upper GI endoscopy with duodenal biopsy in adults; children can often be diagnosed on serology alone.
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Treatment
A strict, lifelong gluten-free diet reverses the intestinal damage and resolves symptoms.
Why this guide matters
Diagnose it properly, treat it properly.
Coeliac is common, underdiagnosed and treatable — but only if the tests are done correctly and the diet is truly strict.
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Test on gluten, not off it
Going gluten-free before testing gives false-negative results — and years of uncertainty.
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Biopsy still matters in adults
Serology is the gateway; duodenal biopsy confirms and grades the damage.
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Strict, lifelong, and reversible
The bowel heals on a truly strict gluten-free diet — but any exposure restarts the damage.
How the diagnosis is made
From suspicion to a confirmed diagnosis.
The steps a UK GP and gastroenterologist will normally follow, in order — so you know what to expect and why.
Phase 1 · Serology
Antibody testing while eating gluten
Phase 2 · Confirming
Endoscopic biopsy and genetics
Phase 3 · Managing
Dietitian, DEXA and annual review
- 01
Serology
Coeliac serology on gluten
Anti-tTG IgA plus total IgA — the recommended first-line test. Must be done while eating gluten normally.
- 02
Serology
IgA-deficient? Switch tests
If total IgA is low, use IgG-based tests (IgG-DGP or IgG-tTG) — otherwise a real coeliac case can be missed.
- 03
Confirming
Upper GI endoscopy + biopsy
In adults, duodenal biopsy confirms villous atrophy and grades the damage (Marsh classification).
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Confirming
HLA-DQ2/DQ8 genetics
A rule-out test only — a negative result excludes coeliac; a positive one does not confirm it.
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Managing
Dietitian consultation
Structured gluten-free education — labels, cross-contamination, eating out, prescriptions.
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Managing
Bone-density DEXA
Baseline bone-density scan — untreated coeliac raises osteoporosis risk.
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Managing
Annual GP or gastro follow-up
Symptom review, adherence, repeat serology and screening bloods — for life.
Typical timeline: 6–12 weeks from first blood test to a confirmed diagnosis and dietitian plan.
Symptoms
What coeliac disease actually looks like.
Coeliac can be classical (bowel symptoms), silent (bloods only) or extra-intestinal (skin, joints, fertility, anaemia). Here is the shape of it.
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Bloating and abdominal pain
Persistent distension and cramps — one of the most common adult presentations.
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Chronic diarrhoea
Loose, pale, offensive stools that improve on a gluten-free diet.
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Weight loss
Unintentional weight loss from malabsorption — sometimes weight gain in milder cases.
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Iron-deficiency anaemia
Unexplained iron, folate or B12 deficiency is a classic coeliac clue.
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Dermatitis herpetiformis
An intensely itchy blistering rash on elbows, knees and buttocks — the skin form of coeliac.
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Infertility, miscarriage
Recurrent miscarriage or unexplained subfertility should trigger coeliac testing.
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Joint pain
Aching joints, sometimes with mouth ulcers or neurological symptoms.
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Red flag
Refractory coeliac disease — persistent symptoms and villous atrophy despite strict gluten-free — needs urgent gastro review.
Treatment
How coeliac disease is treated in the UK.
The only proven treatment is a strict, lifelong gluten-free diet — supported by dietitian input, deficiency correction and long-term surveillance.
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Lifelong strict gluten-free diet
The only treatment. Even small amounts of gluten reactivate the immune response and the intestinal damage.
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Registered dietitian input
Structured education on hidden gluten, cross-contamination and nutritional balance.
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Coeliac UK membership
The national charity — food and drink directory, gluten-free food finder and support network.
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Vitamin and mineral repletion
Iron, folate, B12, vitamin D and calcium as needed — deficiencies are common at diagnosis.
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Bone-density surveillance
Baseline DEXA and repeat scans per NICE — osteoporosis risk stays raised in poorly controlled disease.
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Family screening (first-degree)
Around 1 in 10 first-degree relatives will have coeliac — testing is recommended.
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Follow-up serology
Anti-tTG should fall on a strict gluten-free diet — a useful marker of adherence and response.
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Referral for refractory disease
Persistent symptoms or villous atrophy despite a strict diet — refer to a specialist coeliac centre.
What this guide is based on
The sources behind every claim on this page.
UK national guidance and specialist society standards, current at the time of last review.
Key references
Guidelines and standards we relied on.
A quiet reminder
This guide is for information, not medical advice.
Your GP or gastroenterologist knows your history and can tell you which parts apply to you. If in doubt, seek assessment — especially with any red-flag features.
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NICE. Coeliac disease: recognition, assessment and management (NG20).
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British Society of Gastroenterology. Guidelines on the diagnosis and management of adult coeliac disease.
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Coeliac UK. Patient information and food and drink directory.
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European Society for the Study of Coeliac Disease (ESsCD) guidelines.
Red flags
When coeliac disease needs urgent review.
Most people with coeliac do very well on a strict gluten-free diet. These are the patterns that need urgent specialist assessment.
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Refractory disease despite diet
Persistent symptoms and villous atrophy on a strict gluten-free diet — urgent specialist review.
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Weight loss with treatment
Unexplained weight loss after diagnosis — needs prompt investigation.
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New iron-deficiency anaemia
Falling ferritin or new anaemia despite good adherence — investigate further.
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Osteoporosis
Low bone density on DEXA — treat with vitamin D, calcium and specialist advice.
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Enteropathy-associated T-cell lymphoma
Rare but serious complication of long-standing untreated coeliac — new alarm symptoms warrant urgent workup.
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Pregnancy complications
Recurrent miscarriage, low birth weight or infertility linked to untreated coeliac.
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Dermatitis herpetiformis flare
A blistering, itchy rash flaring up suggests dietary gluten — review adherence and dermatology.
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Children failing to thrive
A child on gluten-free who is not growing normally needs urgent paediatric review.
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Any new GI red flag
Rectal bleeding, obstruction, jaundice or a new abdominal mass — assess urgently.
Living with it
A lifelong condition, but a very manageable one.
Four things make the biggest difference day to day — strict adherence, careful label-reading, community support and regular review.
A quiet reminder
Strict beats almost-strict, every time.
Even small, occasional gluten exposures restart the immune damage — the goal is zero, not less.
- 01 Diet
Strict, not almost-strict
Coeliac is not a spectrum — even small amounts of gluten reactivate the disease. Aim for zero, not less.
- 02 Labels
Read every label, every time
Recipes and manufacturers change. What was safe last month may not be safe now.
- 03 Support
Use the community
Coeliac UK membership, dietitian input and family support make lifelong adherence much easier.
- 04 Reviews
Annual follow-up matters
Yearly bloods, adherence check and symptom review catch drift, deficiencies and complications early.
Frequently asked
Everything we get asked about coeliac disease.
Quick answers on testing, biopsy, the gluten-free diet and family screening.
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What is coeliac disease?
A lifelong autoimmune condition where eating gluten — a protein in wheat, barley and rye — damages the lining of the small bowel. It is not an allergy or intolerance.
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Do I need to be eating gluten to be tested?
Yes. Coeliac serology and biopsy are only reliable if you have been eating gluten regularly (at least one meal a day) for at least six weeks before testing.
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What is the first-line test?
Anti-tissue transglutaminase (anti-tTG) IgA antibodies with total IgA. If total IgA is low, IgG-based tests are used instead.
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Do adults always need a biopsy?
Yes — in the UK, adults are usually confirmed by upper GI endoscopy and duodenal biopsy showing villous atrophy. Children can often be diagnosed on serology alone under specialist paediatric protocols.
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Is gluten-free treatment for life?
Yes. A strict, lifelong gluten-free diet is the only proven treatment — it heals the bowel and prevents complications.
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Should my family be tested?
First-degree relatives (parents, siblings, children) have a much higher risk and should be offered coeliac serology, even if they have no symptoms.
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