Synopsis
Recognise the broad adult coeliac phenotype, preserve gluten exposure for valid testing, apply the current 2026 BSG biopsy or selected no-biopsy pathway, and manage lifelong gluten exclusion, deficiencies and non-response safely.
- Coeliac disease is an immune-mediated enteropathy triggered by gluten in genetically susceptible people; presentation ranges from diarrhoea and weight loss to isolated iron deficiency, osteoporosis, neuropathy or abnormal liver tests.
- Test while the person eats gluten in more than one meal daily for at least six weeks where possible, and advise against starting a gluten-free diet before specialist diagnosis.
- First-line adult serology is total IgA plus IgA tissue transglutaminase; use EMA for appropriate equivocal results and IgG-based testing when IgA deficient.
Key red flags
Profuse diarrhoea, dehydration, major electrolyte disturbance, hypoalbuminaemia or rapid wasting is rare but needs admission, nutrition support and specialist exclusion of infection or refractory disease.
Investigation priorities
Screen symptomatic or at-risk adults while consuming gluten and identify IgA deficiency that changes assay choice.
Management branches
Coeliac disease is suspected from symptoms, deficiency or risk group.
- Confirm adequate gluten exposure and order total IgA with IgA tTG, using alternative assays when IgA deficient.
- Refer positive or strongly suspected cases to gastroenterology without advising gluten exclusion; address severe dehydration or malnutrition immediately.
Key medicines
Oral or intravenous ironSelect a current BNF regimen based on anaemia severity, inflammation, absorption, ongoing loss and tolerance; use intravenous treatment through local governance when oral therapy fails.
Colecalciferol and calciumUse a local loading and maintenance plan based on vitamin D, calcium intake, renal function and bone disease, then reassess.