Assessing Cognitive behavioural Therapy in Irritable Bowel (ACTIB): protocol for a randomised controlled trial of clinical-effectiveness and cost-effectiveness of therapist delivered cognitive behavioural therapy and web-based self-management in irritable bowel syndrome in adults

Introduction: Irritable bowel syndrome (IBS) affects 10–22% of the UK population, with England’s annual National Health Service (NHS) costs amounting to more than £200 million. Abdominal pain, bloating and altered bowel habit affect quality of life, social functioning and time off work. Current treatment relies on a positive diagnosis, reassurance, lifestyle advice and drug therapies, but many people suffer ongoing symptoms. Cognitive behaviour therapy (CBT) and self-management can be helpful, but availability is limited. Methods and analysis: To determine the clinicaland cost-effectiveness of therapist delivered cognitive behavioural therapy (TCBT) and web-based CBT selfmanagement (WBCBT) in IBS, 495 participants with refractory IBS will be randomised to TCBT plus