Exploring the Biopsychosocial Model in Irritable Bowel Syndrome : with emphasis on stress, comorbidities and fatigue

Abstract

Background Irritable bowel syndrome (IBS) is a common, chronic, relapsing, and sometimes disabling, symptom-based disorder of gut brain interactions. It has got a female predominance and occurs in all ages, with a slight decrease among elderly. The IBS symptoms can affect everyday work and social life in addition to an increased use of health care resources. Most IBS patients are diagnosed and helped in primary health care (PHC). For many patients, available treatment is insufficient. It is known that both extraintestinal symptoms such as fatigue, as well as comorbidities such as mood disorders, chronic pain syndromes, and insomnia contribute to the illness burden, often to a larger extent than the gastrointestinal symptoms as such. Eventhough the pathophysiology of IBS is not completely known, it is now conceptualized as a disorder of altered brain-gut interactions, where a biopsychosocial model helps in understanding the symptoms. Exposure to stress is thought to play an important role overall in the pathology of IBS, as well as immune activation at least in a subgroup of patients. This thesis aimed to gain deeper understanding of the biopsychosocial mechanisms of IBS and its associations with stress, comorbidities, and fatigue.