Praxis Medical Insights

Confirming Celiac Disease Exclusion

The American Gastroenterological Association recommends confirming the patient was consuming adequate gluten (at least 10g daily for 6-8 weeks) when serologic testing was performed, as testing on a gluten-free or gluten-reduced diet yields false-negative results 1, 2
The American College of Gastroenterology suggests verifying total IgA level was measured alongside IgA tissue transglutaminase (tTG-IgA), since IgA deficiency occurs in celiac disease and causes false-negative serology 1, 2
The European Society for Pediatric Gastroenterology, Hepatology, and Nutrition recommends ensuring upper endoscopy with duodenal biopsies was performed, not just serology alone—multiple biopsies (ideally 6 total: 1-2 from duodenal bulb and at least 4 from second part of duodenum) are required to confirm or exclude celiac disease 3, 4, 1
If biopsies were not obtained, the diagnosis of celiac disease has not been properly excluded, and upper endoscopy should be performed before labeling this as non-celiac gluten sensitivity 3, 4

The American Academy of Family Physicians notes that HLA-DQ2 and HLA-DQ8 testing has >99% negative predictive value—absence of both alleles essentially rules out celiac disease 4, 1, 2
HLA testing is particularly useful when celiac disease is strongly suspected despite negative serology, in patients with equivocal biopsy findings, or in patients already on a gluten-free diet who were never properly tested 1, 2

The European Society of Gastrointestinal Endoscopy recommends completing the colonoscopy for whatever indication prompted it (age-appropriate screening, alarm symptoms, evaluation of other pathology) 5
The colonoscopy may identify alternative diagnoses that explain the abdominal pain, such as microscopic colitis, inflammatory bowel disease, or other colonic pathology 5

The American Gastroenterological Association suggests considering irritable bowel syndrome, which can coexist with or mimic gluten sensitivity 5
The European Society for Pediatric Gastroenterology, Hepatology, and Nutrition recommends evaluating for small intestinal bacterial overgrowth (SIBO), which causes similar bloating and pain 5
The American College of Gastroenterology suggests testing for lactose or fructose intolerance, which commonly cause abdominal pain and bloating 5
The European Society of Gastrointestinal Endoscopy recommends considering pancreatic exocrine insufficiency if steatorrhea or weight loss is present 5
The American Society for Gastrointestinal Endoscopy suggests evaluating for microscopic colitis if diarrhea is prominent, which may be identified on colonoscopy biopsies 5

The American Academy of Family Physicians notes that diagnosing non-celiac gluten sensitivity without first properly excluding celiac disease with both serology and duodenal biopsies performed while consuming gluten is incorrect 1, 2
The American Gastroenterological Association recommends not relying on symptom improvement with gluten avoidance alone as proof of gluten sensitivity—this has very low positive predictive value and many conditions improve with dietary modification 4
The European Society for Pediatric Gastroenterology, Hepatology, and Nutrition suggests not assuming negative serology excludes celiac disease—seronegative celiac disease occurs, and biopsy remains the gold standard 6, 4, 1
The European Society of Gastrointestinal Endoscopy recommends not delaying indicated colonoscopy to pursue gluten-related workup, as the colonoscopy may reveal the true cause of symptoms 5