Microscopic colitis: a missed diagnosis among patients with moderate to severe irritable bowel syndrome

Abstract

Objective: Irritable bowel syndrome (IBS) is a very common condition in general practise, affecting 10–20% of the population in the Western world. The clinical picture of diarrhoea-predominant IBS (IBS-D) resembles other chronic diarrhoeic conditions, such as microscopic colitis (MC). It is impossible to separate these by clinical examinations or lab-tests that can be done in general practise. The aim of this study was to detect any missed diagnoses when only using a symptom-based approach for the diagnosis of IBS.

Material and methodology: We examined 87 participants diagnosed with IBS by the Rome III criteria. All the participants underwent full clinical examination, lab-tests and colonoscopy including mucosa biopsies for histological examination.

Results: The histological analysis revealed four cases of MC in participants who for years had been diagnosed with IBS. We found no biochemical or clinical markers that made it possible to differentiate between IBS and MC. MC was only found in the participants diagnosed with IBS-D.

Conclusion: When long-lasting, unresolved diarrhoeic conditions are present in patients over 45–50 years of age, colonoscopy with biopsy should be performed to rule out MC and other pathologies before diagnosing IBS. In younger patients with pronounced watery diarrhoea, one should consider colonoscopy individually if there is no response to IBS-treatment.

Keywords:

• Irritable bowel syndrome
• microscopic colitis
• general practise
• differential diagnosis

Disclosure statement

The authors ensure that there is no conflict of interest of any kind.

Funding

The study has been funded by “Helse Nord” Utdanningsfond, UNN Tromsø, as part of the PhD project to one of the authors, Peter Holger Johnsen.

The study has been funded too by the National Centre of Rural Medicine, Department of Community Medicine, UiT.

Ethics and consent

The ongoing REFIT study, where our results are extracted from, has been approved by the regional ethics committee in Troms, North Norway.