K90.0 — Coeliac Disease
Denied29F · investigation — Upper Endoscopy with Duodenal Biopsy
Insurer Rationale
A trial of gluten exclusion is a reasonable first diagnostic and therapeutic step. Endoscopy can be reconsidered only if symptoms persist despite dietary modification.
Clinical Contradiction
Insurer states
“Serological testing is sufficient for coeliac disease diagnosis”
Clinical evidence shows
Positive serology requires duodenal biopsy confirmation per NICE guidelines; concurrent rectal bleeding raises IBD as a confusable diagnosis requiring endoscopic evaluation
Patient risk
Undiagnosed IBD with active inflammation risks stricture, perforation, and malnutrition
Reasoning Chain
Abdominal pain, diarrhoea, fatigue, and rash are shared between coeliac disease and inflammatory bowel disease. Biopsy is the graph-linked discriminator. Starting a gluten-free diet before tissue diagnosis blunts the test and may delay recognition of an inflammatory bowel disease pathway that requires a different escalation strategy.
Reasoning Chain
Findings
Abdominal pain, Chronic diarrhoea, Fatigue, Pruritic rash, Iron-deficiency anaemia
Differential
Coeliac Disease (probable) vs Inflammatory Bowel Disease (not excluded)
Shared findings
Abdominal pain, Diarrhoea, Fatigue, Skin rash
Discriminating investigation — DENIED
Upper Endoscopy with Duodenal Biopsy
Preserves diagnostic accuracy before treatment changes obscure the underlying pathology
Verdict
Denial is clinically unsafe. A therapeutic diet trial is not an adequate substitute for the discriminating biopsy step.
Clinical Evidence
NICE Guideline NG20 — Coeliac disease
Diagnosis
Diagnostic testing should occur before starting a gluten-free diet, and histology remains important when suspicion is high.
BSG Guidelines for Inflammatory Bowel Disease (2024)
Diagnostic confirmation
Endoscopic tissue diagnosis is required when chronic diarrhoea may represent inflammatory bowel disease rather than coeliac disease alone.