Pain is a common symptom of inflammatory bowel disease (IBD) and has a significant impact on patient quality of life. Pain will frequently be the presenting complaint and is experienced throughout the disease course. Up to 70% of patients experience pain in active disease, and up to half (20-50%) of patients will experience pain in remission.

Pain in IBD is widely recognised as a biopsychosocial construct, with visceral hypersensitivity, as well as depressive symptoms, anxiety, stress and fear avoidance correlating positively with IBD-pain. There is increasing understanding of the psychological interaction and need for psychological management within IBD. Psychological therapies such as Cognitive Behavioural Therapy (CBT) and acceptance and commitment therapy (ACT) have been used widely in other conditions, such as chronic pain, fatigue and irritable bowel syndrome (IBS).

Although neither ACT nor CBT have been used specifically for pain in IBD, ACT has become a regular therapy in the management of chronic pain and a large number of studies have found it to be effective, particularly in relation to improving functioning and decreasing distress, quality of life and physical wellbeing.

This study design is a crossover randomised controlled trial of ACT versus treatment-as-usual (TAU) in people with CD and chronic abdominal pain. The research team aim to assess the feasibility of ACT for reducing the impact of abdominal pain and its associated psychological burden in people with Crohn's disease (CD). The study will investigate the acceptability of ACT to people with CD and chronic pain, specifically testing issues of eligibility, recruitment, retention rates, patient experience and performance of proposed outcome measures. This will inform the design of a subsequent large multi-centre randomised controlled trial (RCT) with long-term follow-up.

Aims:

This study aims to assess the feasibility of ACT for reducing the impact of abdominal pain and its associated psychological burden in people with Crohn's disease (CD). The study will investigate the acceptability of ACT to people with CD and chronic pain, specifically testing issues of eligibility, recruitment, retention rates, patient experience and performance of proposed outcome measures. This will inform the design of a subsequent large multi-centre randomised controlled trial (RCT) with long-term follow-up.

Design and setting:

The design is a crossover randomised controlled trial of ACT versus treatment-as-usual (TAU) in people with CD and chronic abdominal pain. The researchers will invite participants aged 18 and over with a diagnosis of CD attending outpatient clinics at Guy's and St Thomas' NHS Foundation Trust and King's College Hospital NHS Foundation Trust to participate. With ~90 patients with CD attending the clinics each week, this represents one of the largest CD cohorts in the UK. Patients with CD attending the outpatients department will be screened for the presence of chronic pain using standard questionnaires. Individual cases will then be reviewed by a gastroenterologist to assess whether their IBD is stable and they are suitable for the study or whether their pain is part of an acute flare which necessitates a change in medical treatment. Only patients where it is thought pain is part of stable chronic disease will be recruited.

Sample size and recruitment:

This is a feasibility study and power calculations for a treatment effect are not applicable. Based on an expected follow-up rate of at least 75%, a two-sided confidence interval will extend no more than 12.5% of the observed proportion with a sample size of 48 patients, thus providing adequate precision estimates. Based on pilot work in the IBD clinics and our previous experience of running RCTs for psychological therapy in IBD, the researchers conservatively estimate that 25% of people approached will be both willing and eligible to participate. As such, a total of 192 people will be approached to meet the recruitment target. WCD will chair biweekly study meetings where recruitment will be reviewed and intensified if falling behind this trajectory.

Randomisation:

Participants will be randomly allocated (1:1) to the intervention or TAU control group using a web-based randomisation service, which employs block randomisation with randomly varying block sizes. Randomisation will be stratified by male/female sex. The researcher analysing the data will not be able to access the data until final database lock.

Intervention:

Half of the cohort (n=24) will be randomised initially to TAU, which will comprise usual care from the CD team and GP but no specific pain intervention except a CCUK information sheet on pain in CD. After completing 24 weeks of TAU, these patients will then crossover to the intervention.

The other half (n=24) will be randomised initially to the intervention group. In addition to TAU, the intervention group will undergo eight 90-minute sessions of weekly ACT in groups of 8 patients, all led by a single clinical psychologist accredited in ACT. The course is based on contemporary ACT models and tailored toward people with IBD with an emphasis on reducing the impact of pain on functioning and quality of life. The research team will develop a manual and observe the sessions for assessment of fidelity.

The manual will be adapted from one developed by co-applicant AD for use with people with IBD. It will be peer-reviewed by experienced ACT practitioners to ensure adherence to the model. Treatment commences with the therapist aiming to foster the therapeutic alliance; exploring the developing of chronic pain; and explaining the treatment model. Subsequent sessions will include exercises to increase patients' awareness of the long-term consequences of struggling to control pain; their willingness to experience pain; the development of personal value-based goals and their engagement in these. Treatment finishes with a review of progress and plans for barriers in future. Patients will be given weekly homework tasks to develop their individual value-based goals and explore barriers that appear for them. The aim of the sessions is to increase patients' awareness of misplaced control strategies and to relinquish these and to increase their value-based activities.

The therapist will maintain a log of completed and non-completed sessions and any adverse events. The therapist will receive weekly supervision with an experienced ACT therapist (AD) to maintain adherence to the treatment protocol; to discuss issues arising from sessions; and plan for subsequent sessions. Any current treatment for pain will continue and be recorded. Changes to analgesia during the study are not restricted and will likewise be recorded. People randomised initially to the intervention group will not subsequently undergo transfer to the TAU group, as outcomes such as pain may already have been improved by the intervention.

Inclusion Criteria:

• Established diagnosis of CD according to clinical notes for a minimum of 6 months

Moderate pain, defined as mean score ≥4/10 on both pain severity and pain interference questions the Brief Pain Inventory (BPI) - a validated cut-off to define moderate pain

Duration of pain of at least 3 months

No changes to CD medication made for the previous 2 months

Exclusion Criteria:

• Diagnosis of ulcerative colitis or indeterminate colitis

Known diagnosis of dementia/psychosis or expressing active suicidal ideation on clinical assessment

Currently undergoing other psychological therapy

Primary source of pain is non-abdominal

Non-fluency in verbal English

Pain is identified as a part of acute flare where immediate change in medical treatment is more appropriate

Not possible die to study design