Psychosocial predictors of self-reported fatigue in patients with moderate to severe irritable bowel syndrome.

The objective of this study was to assess the level, impact, and predictors of fatigue in patients with moderate to severe irritable bowel syndrome (IBS). One hundred seventy five patients meeting Rome III criteria for IBS completed a variety of measures including the vitality scale of the SF-12, IBS-Symptom Severity Scale, IBS-QOL, Brief Symptom Inventory-18, Screening for Somatoform Symptoms (SOMS-7), and a semi structured clinical interview (IBS-PRO) as part of a pretreatment evaluation of an NIH funded clinical trial of cognitive behavior therapy for IBS. Fatigue was the third most common somatic complaint, reported by 61% of the patients. Levels of fatigue were associated with both somatic (more severe IBS symptoms, greater number of unexplained medical symptoms), behavioral (frequency of restorative experiences) and psychological (e.g., trait anxiety, depression) outcomes after holding constant confounding variables. The final model in multiple regression analyses accounted for 41.6% of the variance in self-reported fatigue scores with significant predictors including anxiety sensitivity, perceived stress, IBS symptom severity, restorative activities and depression. The clinical implications of data as they relate to both IBS and CBT in general are discussed in the context of attention restoration theory.