Summary<\/strong><\/p>\n Current best practice, in line with BSG, ESPGHAN and ACG guidance, is to take biopsies from both the duodenal bulb (D1) and the distal duodenum (D2 \/ D3), placed in separate pots. At least one (preferably two) bulb biopsies plus four or more distal duodenal biopsies is the standard recommendation. D2 remains the principal diagnostic site, but adding D1 increases diagnostic sensitivity, particularly for ultra-short coeliac disease and paediatric cases.<\/p>\n Traditional teaching was to biopsy the second part of the duodenum and to avoid the bulb. The rationale was that the bulb is architecturally complex \u2014 Brunner glands distort villous architecture, peptic injury and gastric metaplasia are common, and orientation in the histology laboratory is often poor. These features were felt to give unreliable assessment of villous atrophy and to risk false-positive interpretations of Marsh 1\u20133 change.<\/p>\n A series of studies in the 2000s and 2010s showed that a meaningful minority of coeliac patients have disease that is confined to, or most marked in, the bulb. Bonamico and colleagues demonstrated that taking bulb biopsies in addition to distal duodenum increased the diagnostic yield in children, and identified the 9 o’clock and 12 o’clock positions as the most informative bulb sites. Evans et al. and subsequent adult series have confirmed that around 5\u201310% of adult coeliac patients have lesions limited to or more severe in the bulb (ultra-short coeliac disease), and that omitting D1 would miss these cases.<\/p>\n Bulb mucosa is intrinsically harder to assess. Brunner gland lobules push villi apart and shorten them, gastric metaplasia is common, and peptic duodenitis can produce IEL increases unrelated to gluten. Bulb-only abnormalities should therefore be interpreted in the context of serology, HLA status, and the distal duodenal appearances before a confident coeliac diagnosis is made.<\/p>\n Biopsy both. D2 remains the principal diagnostic site, but the addition of separately-potted bulb biopsies materially improves sensitivity, particularly for ultra-short coeliac disease and in children. This is the position of the BSG, ESPGHAN and ACG guidelines.<\/p>\n Summary Current best practice, in line with BSG, ESPGHAN and ACG guidance, is to take biopsies from both the duodenal bulb (D1) and the distal duodenum (D2 \/ D3), placed in separate pots. At least one (preferably two) bulb biopsies plus four or more distal duodenal biopsies is the standard recommendation. D2 remains the principal […]<\/p>\n","protected":false},"author":1119,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[290084,318392],"tags":[],"class_list":["post-132","post","type-post","status-publish","format-standard","hentry","category-gastro-intestinal-pathology","category-trainee"],"yoast_head":"\nHistorical position: D2 only<\/h2>\n
Why D1 was added: ultra-short coeliac disease<\/h2>\n
Practical protocol<\/h2>\n
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Caveats with bulb biopsies<\/h2>\n
Bottom line<\/h2>\n
Key references<\/h2>\n
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