title: Clinical features of microscopic colitis in a nation-wide follow-up study in Iceland.
abstract: OBJECTIVE
  The long-term natural history of collagenous colitis (CC) and lymphocytic colitis (LC) is not well known. The few reports available that address these issues have a limited follow-up. The aims of this study were to evaluate the natural history of microscopic colitis (MC), to describe the treatment medications prescribed and to assess the use of non-steroidal anti-inflammatory drugs (NSAIDs) in MC.
  
  
  METHODS
  This study is based on an earlier epidemiological study conducted in Iceland where 125 patients with MC (71 with CC and 54 with LC) were diagnosed in the period 1995-99. All patients still alive and available were questioned about symptoms, treatment and NSAID use in the 3 months preceding the interview.
  
  
  RESULTS
  In a mean follow-up time of 6.4 years from diagnosis, 15% of the patients had diarrhoeal symptoms more than once a week, 30% less than once a week and 55% had no diarrhoea. Abdominal pain was reported in 18% of the patients. There was no statistically significant difference in symptoms of CC and LC patients. Forty-eight patients (50%) were receiving medication for MC, 16% used aminosalicylates and 14% corticosteroids. Patients using medication for MC had significantly more diarrhoeal symptoms compared with those who did not (p = 0.002). Patients using NSAIDs regularly or as required, statistically did not have more symptoms related to MC than non-NSAID users.
  
  
  CONCLUSIONS
  Only a minority of patients with MC had diarrhoea more than once a week in a long-term follow-up and the symptom pattern was similar between CC and LC patients. The use of NSAIDs was not associated with more diarrhoeal symptoms.
authors.affiliation: Department of Medicine, Division of Gastroenterology, Landspitali University Hospital, Reykjavik, Iceland.
authors.forename: Olafur A
authors.initials: OA
authors.lastname: Sveinsson
authors.forename: Kjartan B
authors.initials: KB
authors.lastname: Orvar
authors.forename: Sigurbjorn
authors.initials: S
authors.lastname: Birgisson
authors.forename: Margret
authors.initials: M
authors.lastname: Agnarsdottir
authors.forename: Jon Gunnlaugur
authors.initials: JG
authors.lastname: Jonasson
mesh_terms: D000368:Aged; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000627:therapeutic use*; D046728:Colitis, Microscopic / Q000175:diagnosis* / Q000188:drug therapy / Q000453:epidemiology; D005260:Female; D005500:Follow-Up Studies; D005938:Glucocorticoids / Q000627:therapeutic use*; D006801:Humans; D007055:Iceland / Q000453:epidemiology; D015994:Incidence; D008297:Male; D012189:Retrospective Studies; D012720:Severity of Illness Index; D016896:Treatment Outcome
chemical_list: D000894:Anti-Inflammatory Agents, Non-Steroidal; D005938:Glucocorticoids