title: Subjective health complaints and quality of life in patients with irritable bowel syndrome following Giardia lamblia infection: a case control study.
abstract: OBJECTIVE
  Irritable bowel syndrome (IBS) is associated with unexplained medical symptoms, and the degree of somatic comorbidity may indicate whether the aetiology of IBS is predominantly psychological or biological in origin. The purpose of this study was to examine the comorbidity and quality of life of patients with IBS following infection with Giardia lamblia.
  
  
  METHODS
  Sixty-seven consecutive patients with persistent abdominal symptoms, initiated by an acute infection with G. lamblia, completed questionnaires for scoring of subjective health complaints (SHC) and quality of life (Short-form Nepean Dyspepsia Index (SF-NDI)). The scores were compared with corresponding scores in persons from the general population (n=70).
  
  
  RESULTS
  Compared with controls, each of the two groups of patients, those with present (n=17) and those with cured (n=50) G. lamblia infection, had significantly higher scores (p<0.0001) on SHC. However, subscores on somatic comorbidity (musculoskeletal pain) were low and similar to those in the general population (OR 1.2 (0.51-2.73)). Quality of life was substantially impaired in the patients; sum scores 30.0+/-8.0 (mean+/-SD) and 31.7+/-9.3 in the patient groups and 13.5+/-6.8 in the general population (p<0.0001).
  
  
  CONCLUSIONS
  Patients with post-giardiasis IBS suffer very little somatic comorbidity, suggesting that the aetiology of this form of postinfective IBS is predominantly biological in origin and may thus differ from the more common, non-postinfective forms of IBS. The combination of persisting abdominal symptoms and psychological distress might be a perpetuating factor contributing to low quality of life.
authors.affiliation: Institute of Medicine, University of Bergen, Haukeland University Hospital, Bergen, Norway. mette.morken@helse-bergen.no
authors.forename: Mette H
authors.initials: MH
authors.lastname: Morken
authors.forename: Ragna A
authors.initials: RA
authors.lastname: Lind
authors.forename: Jørgen
authors.initials: J
authors.lastname: Valeur
authors.forename: Ingvard
authors.initials: I
authors.lastname: Wilhelmsen
authors.forename: Arnold
authors.initials: A
authors.lastname: Berstad
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000704:Analysis of Variance; D000818:Animals; D016022:Case-Control Studies; D005260:Female; D016829:Giardia lamblia; D005873:Giardiasis / Q000382:microbiology / Q000523:psychology*; D006305:Health Status Indicators; D006801:Humans; D043183:Irritable Bowel Syndrome / Q000469:parasitology / Q000523:psychology*; D008297:Male; D008875:Middle Aged; D010147:Pain Measurement; D011788:Quality of Life / Q000523:psychology*; D011795:Surveys and Questionnaires