Coeliac disease is more common than most people realise and more variable in its presentation than the classic picture of chronic diarrhoea and failure to thrive suggests. Many children with coeliac disease have subtle or non-specific symptoms for years before diagnosis, and some have no digestive symptoms at all. Understanding what to look for and how the diagnosis is made matters because the condition is very manageable once identified.
The key practical point for parents of children who may need testing: do not put your child on a gluten-free diet before the testing is done. This reverses the immune change that the tests detect and makes accurate diagnosis impossible.
Healthbooq (healthbooq.com) covers digestive and nutrition conditions through the early years, including guidance on when to seek assessment.
What Coeliac Disease Is
Coeliac disease is an autoimmune condition. When someone with coeliac disease eats gluten (the protein found in wheat, barley, and rye), the immune system reacts by attacking the lining of the small intestine, specifically the villi, small finger-like projections that dramatically increase the surface area available for nutrient absorption. Damaged villi mean reduced absorption of nutrients, which can lead to deficiencies in iron, calcium, vitamin D, folate, and other essential nutrients.
It affects around 1 per cent of the UK population, with a higher prevalence in people who have Down's syndrome, type 1 diabetes, or autoimmune thyroid disease, and in first-degree relatives of people with coeliac disease (risk around 1 in 10).
Gluten sensitivity is not the same as coeliac disease. Non-coeliac gluten sensitivity is a condition where gluten causes symptoms but does not produce the intestinal damage or antibodies characteristic of coeliac disease. Distinguishing between them matters for management.
How It Presents in Children
The classic presentation in young children is chronic diarrhoea (often pale, fatty, and foul-smelling), abdominal bloating and distension, faltering growth, and misery after meals. This picture prompts investigation relatively quickly.
But many children present differently. Constipation, not diarrhoea, is the symptom in some. Abdominal pain alone, without changes in stool pattern, is common. Iron deficiency anaemia that does not respond to iron supplementation is a recognised presentation. Fatigue and low energy out of proportion to any other explanation. Dental enamel defects. Delayed puberty. Recurrent mouth ulcers.
Some children are identified through family screening after a parent or sibling is diagnosed, rather than through their own symptoms.
Diagnosis
Diagnosis follows a two-step process and requires the child to be eating gluten at the time of testing. Testing while on a gluten-free diet will give false-negative results.
The first step is a blood test measuring IgA anti-tissue transglutaminase (TTG) antibodies, which are elevated in active coeliac disease. Total IgA is measured alongside this, because IgA deficiency (affects around 1 in 400 people) would cause a false-negative coeliac antibody result.
A positive antibody test leads to referral to a paediatric gastroenterologist. The definitive diagnosis is by small bowel biopsy, usually performed at endoscopy under sedation or light anaesthesia. NICE guidance (NG20) for children has changed in recent years and may allow biopsy to be bypassed in children with very high antibody levels (ten times the upper limit of normal) and positive genetic markers, but this is decided on a case-by-case basis by the specialist.
GP referral is the starting point if coeliac disease is suspected. The GP will arrange the blood tests and refer based on results.
The Gluten-Free Diet
The treatment is a strict lifelong gluten-free diet. Gluten must be entirely excluded: even small amounts cause ongoing intestinal damage even if symptoms do not occur. Hidden gluten in processed foods, cross-contamination in shared fryers or on cutting boards, and the gluten content of communion wafers, beer, and some medications are practical considerations that become important once the diet is established.
Foods containing wheat, barley, or rye (including most bread, pasta, cereals, and many processed foods) are excluded. Foods that are naturally gluten-free include rice, potatoes, corn, oats (though oats require specific certified gluten-free versions as standard oats are usually contaminated), meat, fish, fruit, vegetables, eggs, and dairy.
Many mainstream supermarkets stock a reasonable range of gluten-free products. Coeliac UK (coeliac.org.uk) provides a food checker app, a regularly updated safe and crossed grain symbols guide, and local support groups. The app is practically useful and parents of newly diagnosed children find it essential.
On the NHS, children with coeliac disease are entitled to some gluten-free staple foods on prescription, though this varies by area and the range available has reduced over recent years.
Follow-up with a paediatric dietitian is part of standard care and important: the diet is restrictive, and nutritional completeness needs to be monitored, particularly for fibre, calcium, and B vitamins.
Family Screening
When a child is diagnosed, first-degree relatives (parents, siblings) have a 1 in 10 chance of also having coeliac disease. Many will be asymptomatic. NICE guidance recommends offering blood testing to all first-degree relatives.
Key Takeaways
Coeliac disease is an autoimmune condition in which ingestion of gluten triggers damage to the small intestine lining, impairing nutrient absorption. It affects around 1 in 100 people in the UK, though many remain undiagnosed. Symptoms in children vary widely and include diarrhoea, constipation, abdominal pain, poor growth, fatigue, and iron deficiency anaemia; some children have few gastrointestinal symptoms. Diagnosis requires blood tests (for anti-tissue transglutaminase antibodies) followed by a small bowel biopsy; the child must be eating gluten at the time of testing. Treatment is a strict lifelong gluten-free diet. First-degree relatives of someone with coeliac disease have a 1 in 10 chance of also having it and should be tested.
