Low prevalence of ‘classical’ microscopic colitis but evidence of microscopic inflammation in Asian Irritable Bowel Syndrome patients with diarrhoea

Abstract

BackgroundThere is increasing evidence for the role of microscopic inflammation in patients with IBS. We aimed to examine the prevalence of microscopic colitis and inflammation in Malaysian IBS patients with diarrhoea (IBS-D).MethodsConsecutive patients who met the Rome III criteria for IBS-D and asymptomatic controls were prospectively recruited. Colonoscopy was performed in all study subjects and systematic biopsies taken from all segments of the colon. The diagnosis of lymphocytic colitis and collagenous colitis was made using previously defined criteria. Patients with post infectious IBS were excluded.Results120 subjects (74 IBS-D, 46 controls) were recruited during the study period. In the IBS-D group, the colonoscopic (macroscopic) findings were as follows; normal findings n = 58 (78.4%), diverticula disease n = 5 (6.8%), diminutive polyps n = 9 (12.2%) and haemorrhoids n = 2(2.7%). No subject under the age of 40 had any significant findings. Microscopically, there was only one case (1.3%) with histology consistent with collagenous colitis. However, the IBS-D patients had a higher prevalence of moderate microscopic inflammation (n = 11, 14.9%) compared to controls (n = 1, 2.2%) (p = 0.005).Conclusions‘Classical’ microscopic colitis is uncommon in Malaysian patients with IBS-D but a significant number of adults showed evidence of microscopic inflammation.

Systematic review with meta‐analysis: diagnostic overlap of microscopic colitis and functional bowel disorders

“…However, two new documents were retrieved after reference tracking. In the end #bib26 studies (comprising 23 full papers and three abstracts, nine of which dealt primarily with MC while the remaining 17 focused on functional bowel disorders) were included in the quantitative summaries of our systematic review (Figure ). Eleven studies were carried out in Europe, seven in North America, six in Asia, one in the Middle East (Iran) and one in New Zealand.…”

“…Interest in proper identification of underlying organic gastrointestinal disease among patients with suspected IBS has increased over the last decade due to the potential implications for its therapeutic management. In particular, several recent studies have reported a diagnostic overlap between MC and IBS (especially in patients with IBS‐D or functional diarrhoea) with conflicting results . In fact, increased awareness on the part of clinicians, endoscopists and pathologists alike is needed to reach a definitive diagnosis of MC due to the relationship between MC and IBS has neither been universally documented nor assessed according to the latest updated studies.…”

Epidemiological and clinical perspectives on irritable bowel syndrome in India, Bangladesh and Malaysia: A review

“…A study of 120 subjects in a Malaysian tertiary institution found a very low (1.3% only) prevalence of collagenous colitis among 120 IBS subjects. However, IBS-D patients had a higher prevalence of moderate non-specific, microscopic inflammation compared to controls (14.9% vs 2.2%, P = 0.005), suggesting that either occult infection or other causes of inflammation may be contributory towards IBS-D sub-types[ 69 ].…”

Optimal management of collagenous colitis: a review

“…A Korean study of chronic diarrhea detected CC in 4% of patients similar to rates recorded in the western world 16 and has been reported with lower prevalence rates in Indian and Malaysian studies. 17 , 18 …”