Objective: The relationship between coeliac disease and inflammatory bowel disease (IBD) is controversial. The aim of this study was to determine the prevalence of coeliac disease in IBD and the prevalence of IBD in coeliac disease.
Material and methods: Patients were enrolled from specialist IBD and coeliac clinics. Antigliadins, endomysial, tissue transglutaminase antibody and total IgA levels were measured in IBD patients. Patients with positive antibodies were offered a duodenal biopsy. The notes on coeliac patients were reviewed for colonoscopic and biopsy findings. Controls were recruited from the local population.
Results: The study included 305 patients with coeliac disease, 354 with IBD and 601 healthy controls. The IBD group comprised 154 ulcerative colitis (UC) cases, 173 Crohn's disease, 18 indeterminate colitis and 9 cases of microscopic colitis. Forty-seven patients had positive antibodies and 3 had villous atrophy on biopsy. All three patients had positive anti-tissue transglutaminase antibodies but only two were endomysial antibody (EMA) positive. Ten coeliac patients had IBD (5 UC and 5 lymphocytic colitis). Five controls had coeliac disease and 2 had IBD (1 Crohn's disease and 1 UC). Stepwise multiple logistic regression showed only antibody positivity as being significant (p<0.0001).
Conclusions: The prevalence of IBD in coeliac disease was increased 10-fold compared with that in controls (odds ratio 9.98, 95% CI 2.8-45.9, p=0.0006), while the prevalence of coeliac disease in IBD was comparable with that in controls (odds ratio 1.02, 95% CI, 0.24-4.29, p=1.0).