The association of coeliac disease and microscopic colitis: a large population-based study

An association between microscopic colitis and coeliac disease (CD) has been suggested in literature; however, population-based data are limited.

To estimate the degree of association between these two diseases and to identify possible risk factors for disease concomitance.

A population-based review of all patients diagnosed with CD and microscopic colitis in a large Canadian centre over a 5-year period. Endoscopy and pathology databases were searched to identify all cases of CD and microscopic colitis diagnosed within the Calgary Health Region between 2004 and 2008. Incidence rates were age-standardised and gender-standardised to 2006 Canadian Census data. standardised incidence ratios (SIR) were used to assess disease concomitance.

Over 5 years, 763 patients were diagnosed with CD, and 1106 were diagnosed with microscopic colitis. The standardised incidence of CD ranged from 10.4 to 15.7 per 100,000 population. The standardised incidence of microscopic colitis ranged from 16.9 to 26.2 per 100,000 population. Forty patients were diagnosed with both CD and microscopic colitis, 21 of whom were middle aged (40-60 years) females. Within the CD cohort, microscopic colitis occurred at an annual rate of 11.4 per 1000 cases of CD with an overall SIR of 52.7.

There exists a strong association between microscopic colitis and CD with disease concomitance being approximately 50-times that expected in the general population. The concomitant diagnosis of CD and microscopic colitis largely occurs in middle-aged women. Therefore, middle-aged women with CD and diarrhoea as a presenting or persistent symptom should undergo lower endoscopy with biopsies to rule out microscopic colitis.