Fatigue and IBD
Fatigue is a normal psycho-physiological state or symptom in all humans, although the ‘raison d’être’ for fatigue remains obscure. Theoretically, fatigue in humans appears to exist as a protective mechanism, intervening where optimal performance is no longer achievable, and thus, preventing injury or harm to the person from ongoing (over)activity. For instance, in the case of systemic infection, fatigue is a major component of ‘sickness behaviour’, limiting activity in order to divert resources from ‘ergotropic’ to ‘trophotropic’ systems (Romani 2008). However, in chronic diseases like inﬂ ammatory bowel disease (IBD), for some reason, there is an increasingly recognised propensity for ‘pathological’ fatigue to occur, not only purely as a homeostatic function, but rather a pervasive, potentially unrelenting symptom in its own right. The fatigued patient is therefore a major challenge for the clinician, as current research suggests that the aetiopathogenesis of fatigue is a complex web of biological, psychological and behavioural components, of which each must somehow be addressed (van Langenberg and Gibson 2010).