Cumulative Effects of Psychologic Distress, Visceral Hypersensitivity, and Abnormal Transit on Patient-reported Outcomes in Irritable Bowel Syndrome.

Abstract

Little is known about the link between pathophysiologic factors and symptoms of irritable bowel syndrome (IBS), or whether these factors have cumulative effects on patient-reported outcomes (PROs). We investigated whether pathophysiologic alterations associated with IBS have cumulative or independent effects on PROs. We performed a retrospective analysis of data from 3 cohorts of patients with IBS (n = 407; 74% female; mean age, 36 ± 12 years), based on Rome II or Rome III criteria, seen at a specialized unit for functional gastrointestinal disorders in Sweden from 2002 through 2014. All patients underwent assessments of colonic transit time (radiopaque markers); compliance, allodynia, and hyperalgesia (rectal barostat); anxiety and depression (Hospital Anxiety and Depression scale), as pathophysiologic factors. Dysfunction was defined by available normal values. PROs included IBS symptom severity, somatic symptom severity, and disease-specific quality of life. Allodynia was observed in 36% of patients, hyperalgesia in 22%, accelerated colonic transit in 18%, delayed transit in 7%, anxiety in 52%, and depression in 24%: each of these factors was associated with severity of at least 1 symptom of IBS. Rectal compliance was not associated with more severe symptoms of IBS. At least 3 pathophysiologic factors were present in 20% of patients, 2 in 30%, 1 in 31%, and none in 18%. With increasing number of pathophysiologic abnormalities, there was a gradual increase in IBS symptom severity (P < .0001) and somatic symptom severity (P < .0001), and a gradual reduction in quality of life (P < .0001). Visceral hypersensitivity, including allodynia and hyperalgesia, abnormal colonic transit, and psychologic factors are all associated with IBS symptoms. These factors have a cumulative effect on gastrointestinal and nongastrointestinal symptoms, as well as on quality of life, in patients with IBS and are therefore relevant treatment targets.