title: 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.
  
  
  METHODS
  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.
  
  
  CONCLUSIONS
  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.
authors: a Sjøkanten legesenter and Bjarkøy legekontor , Harstad , Norway.
authors: Frank
authors: F
authors: Hilpüsch
authors: b Department of Gastroenterology , University Hospital of Northern Norway , Harstad , Norway.|c Department of Gastroenterology , The Arctic University of Norway , Tromsø , Norway.
authors: Peter Holger
authors: PH
authors: Johnsen
authors: c Department of Gastroenterology , The Arctic University of Norway , Tromsø , Norway.|d Department of Gastroenterology Tromsø , University Hospital of Northern Norway , Norway.
authors: Rasmus
authors: R
authors: Goll
authors: b Department of Gastroenterology , University Hospital of Northern Norway , Harstad , Norway.
authors: Per Christian
authors: PC
authors: Valle
authors: e Department of Clinical Pathology , University Hospital of Northern Norway , Tromsø , Norway.
authors: Sveinung Wergeland
authors: SW
authors: Sørbye
authors: d Department of Gastroenterology Tromsø , University Hospital of Northern Norway , Norway.|f Department of Community Medicine, UiT , National Centre of Rural Medicine, The Arctic University of Norway , Tromsø , Norway.
authors: Birgit
authors: B
authors: Abelsen
mesh_terms: D000328:Adult; D000368:Aged; D001706:Biopsy; D046728:Colitis, Microscopic / Q000175:diagnosis* / Q000473:pathology; D003113:Colonoscopy; D003937:Diagnosis, Differential; D003967:Diarrhea / Q000209:etiology; D005260:Female; D058006:General Practice; D006801:Humans; D043183:Irritable Bowel Syndrome / Q000175:diagnosis* / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D009664:Norway; D055815:Young Adult
keywords: Irritable bowel syndrome; differential diagnosis; general practise; microscopic colitis