Assessing the Burden of Irritable Bowel Syndrome in the United Kingdom

Introduction: Irritable bowel syndrome (IBS) does not seem to confer an increased mortality risk but the burden of the disorder on individuals, the health service, and society seems to be substantial. The aim of this thesis was to examine these issues.

Methods: In cross-sectional surveys recruiting individuals with IBS from the community, the impact of IBS on work and activities of daily living, the quality of life of individuals with IBS, the willingness to accept risk with medication in return for symptom cure, and the annual direct healthcare cost of IBS in the UK were examined. In two longitudinal follow-up studies in a separate cohort of individuals with IBS, the impact of a change from Rome III to Rome IV criteria for IBS, and the cumulative effect of psychological comorbidity on the prognosis of the disorder were assessed.

Results: In total, 752 participants with Rome IV-defined IBS were recruited from the community. Individuals with IBS reported a substantial impact of IBS on work leading to absenteeism and loss of work productivity, and reported interference of their symptoms with activities of daily living. Quality of life among those with Rome III or IV IBS was comparable with chronic organic conditions and was poorer amongst those with more severe gastrointestinal and psychological symptoms. A standard gamble demonstrated that individuals with Rome IV IBS were willing to accept a median 2% risk of death from a hypothetical medication in return for a 98% chance of permanent cure of their IBS. The mean annual direct healthcare cost of IBS was estimated to be between £1.2 billion and £2 billion. The two longitudinal follow-up studies demonstrated that those with Rome IV IBS, compared with those with Rome III IBS, and those with more psychological comorbidities have a worse prognosis.

Conclusion: IBS causes substantial burden to the individual, the health service, and society. Quantifying this accurately provides a strong mandate for adequate funding into IBS research. Changes in clinical practice, such as making a positive diagnosis of IBS, routine psychological assessments, and earlier introduction of brain-gut behavioural therapy, may help reduce the burden of IBS.