Introduction Increased incidence of both lymphocytic (LC) and collagenous (CC) colitis, often described under the umbrella term of microscopic colitis (MC), is being seen globally. The aetiology, pathogenesis and incidence of MC is yet to be well established. However, not all patients with diarrhoea undergo biopsies to cheque for MC. We aimed to investigate our patient population attending for colonoscopy with symptoms of diarrhoea to assess the proportion of patients undergoing random colon/rectal biopsies to look for MC as well as the incidence of LC/CC in our population.

Methods Retrospective analysis of the endoscopy database was performed to identify patients presenting from January - December 2011 for colonoscopy with diarrhoea. Patients with a complete colonoscopy with macroscopically normal mucosa or findings unrelated to symptoms were included. MC patients were identified by histology.

Results A total of 939 colonoscopies were performed during this period for either diarrhoea or undocumented symptoms. Of these, 186 were for patients with definite diarrhoea and were both complete as well as macroscopically normal. Of these, 123 (66%) had random biopsies taken. 2 patients i.e 1% of all diarrhoea patients undergoing colonoscopy (1.6% of all diarrhoea patients undergoing colonoscopy and random biopsies) were diagnosed with CC while 5 patients i.e 2.7% of all diarrhoea patients undergoing colonoscopy (4.1% of all diarrhoea patients undergoing colonoscopy and random biopsies) were diagnosed with LC. Thus, 3.8% of all diarrhoea patients undergoing colonoscopy were diagnosed with MC (5.7% of all diarrhoea patients undergoing colonoscopy and random biopsies).

Conclusion Though there appears to be an increase in incidence of MC documented in literature, we did not find this in our endoscopy unit. This may be due to variability in endoscopists resulting in inadequate random biopsies being undertaken during colonoscopy performed to investigate diarrhoea. We are currently undertaking an audit to ensure improved management of these patients as well as improve our accuracy in the assessment of the true incidence of MC.

Disclosure of Interest None Declared.

Reference

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