title: Symptoms of irritable bowel syndrome in patients with inflammatory bowel disease: examining the role of sub-clinical inflammation and the impact on clinical assessment of disease activity.
abstract: BACKGROUND
  Symptoms compatible with irritable bowel syndrome (IBS) are frequently present in patients with inflammatory bowel disease (IBD); however, the cause of this phenomenon is unclear.
  
  
  OBJECTIVE
  To determine the different contributions of 'true IBS' and sub-clinical inflammation in producing IBS-type symptoms in IBD patients, and to ascertain the impact these symptoms have on the clinical assessment of IBD activity.
  
  
  METHODS
  In this cross-sectional study, 169 IBD patients completed questionnaires to assess disease activity, presence of IBS-type symptoms, and levels of anxiety and depression. Stool samples were collected for analysis of faecal calprotectin (FC).
  
  
  RESULTS
  IBS-type symptoms were significantly more common in female patients (OR = 4.64, 1.55-13.88) and were associated with higher levels of anxiety (OR = 1.11, 1.01-1.21). There was no statistical difference between the FC levels of patients in clinical remission with IBS-type symptoms compared with those without (median values = 111 μg/g vs. 45.5 μg/g respectively, P = 0.171). The prevalence of IBS-type symptoms in patients with a normal FC level was 31%.
  
  
  CONCLUSIONS
  A substantial number of IBD patients with normal faecal calprotectin level experience IBS-type symptoms. These patients exhibit similar features to people diagnosed with IBS in the general community, suggesting that the conditions are not mutually exclusive and may coexist in a considerable number of IBD patients. A systematic diagnostic approach is required to assess IBD patients with IBS-type symptoms as sub-clinical inflammation may play a role in a proportion of cases.
authors.affiliation: Department of Gastroenterology, University Hospital Llandough, Cardiff, Wales, UK. jamesberrill1@doctors.org.uk
authors.forename: J W
authors.initials: JW
authors.lastname: Berrill
authors.forename: J T
authors.initials: JT
authors.lastname: Green
authors.forename: K
authors.initials: K
authors.lastname: Hood
authors.forename: A K
authors.initials: AK
authors.lastname: Campbell
mesh_terms: D000328:Adult; D001007:Anxiety / Q000523:psychology; D003430:Cross-Sectional Studies; D003863:Depression / Q000523:psychology; D018450:Disease Progression; D005260:Female; D006801:Humans; D007249:Inflammation / Q000150:complications* / Q000523:psychology; D015212:Inflammatory Bowel Diseases / Q000150:complications / Q000175:diagnosis* / Q000523:psychology; D043183:Irritable Bowel Syndrome / Q000150:complications / Q000175:diagnosis* / Q000523:psychology; D008297:Male; D008875:Middle Aged; D012720:Severity of Illness Index; D011795:Surveys and Questionnaires