This study is examining fatigue in patients with Inflammatory Bowel Disease (IBD). IBD includes Ulcerative Colitis (UC) and Crohn's disease. These are inflammatory conditions of the gastrointestinal tract and are associated with symptoms including diarrhoea, rectal bleeding and abdominal pain. Fatigue is a common problem for patents with IBD, affecting 80% of patients with active disease.This study aims to identify all IBD patients with fatigue. Initially, the investigators will address all medical causes of fatigue in line with current practice, using a stepwise approach (e.g. assessing for and treating active inflammation, anaemia as well as electrolyte, hormone and vitamin imbalances). The aim is to treat fatigue using a detailed algorithm, as fatigue is often a consequence of multiple issues in IBD patients. The investigators will assess the role of physical activity, nutritional status and psychological wellbeing in fatigue persisting in medically-optimised IBD patients. In addition, the contribution of the microbiome to fatigue will be assessed. For those in whom these factors are identified alongside persistent fatigue, interventions have been designed to address these factors and the resulting fatigue.

This is a longitudinal research study to define the extent and severity of fatigue in IBD patients; patients will be followed for a period of weeks to months depending on each individual participants needs. The study will be a cross-sectional in nature initially. The study is open to all mobile and non-pregnant Crohn's disease and ulcerative colitis patients between the ages of 18 and 70 years. Recruitment will take place in St Vincent's University Hospital, an academic teaching hospital, from Gastroenterology clinics as well as through the IBD clinical nurse specialist service. Patients that meet inclusion criteria will be recruited from clinics and/or through the IBD clinical nurse specialist service. The recruited subjects will be briefed on the inclusion and exclusion criteria, the nature of the study as well as the outcome measure. Participants will receive information packs and consent forms. All participants will have the opportunity to withdraw at any stage during the study and this will be explained to them. Patients will be followed up as clinically necessary within the parameters of the study and at the IBD clinic at clinically appropriate intervals. All patients attending the IBD service that meet inclusion criteria will be given the opportunity to participate in this study. Information will be collected at baseline including demographic data, IBD history and symptoms, co-morbidities and disease activity.

There are seven elements to this study that will be carried out in parallel:

1. An initial cross-sectional study to define the extent and severity of fatigue in IBD subjects incorporating a simple fitness test protocol. All patients attending the IBD service that meet inclusion criteria will be given the opportunity to participate in this study. Information will be collected at baseline including demographic data, IBD history and symptoms, co-morbidities and disease activity. Patients will have baseline blood tests taken to assess for causes of fatigue as well as faecal calprotectin to assess for evidence of inflammation. Patients without fatigue will at this point exit the study and will not require any further follow up. In those with fatigue, disease activity will be assessed and treated in accordance with current clinical guidelines (as would be standard of care). Fatigued patients will also be assessed for anaemia and other medical causes of fatigue and treated for these as per current clinical practice guidelines.
2. A longitudinal study of contemporary treatment for active disease and its effect on fatigue. Patients with active disease and fatigue will be followed prospectively while undergoing treatment for active IBD with the IBD team. Each patient's response to treatment will vary and so the exact time point between disease treatment and resolution of disease activity cannot be clearly defined. The study outcomes will be assessed at recruitment and when participants achieve clinical and biochemical remission. If fatigue resolves, participants will exit the study at this point. If fatigue persists, further assessments will take place as detailed below.
3. A longitudinal study assessing anaemia and the effect of treatment on fatigue in those subjects with inactive IBD. Patients with anaemia and fatigue will be followed prospectively while undergoing treatment for anaemia with the IBD team. Each patient's response to treatment will vary and so the exact time point between anaemia treatment and resolution of anaemia cannot be clearly defined. The study outcomes will be assessed at recruitment and when anaemia has resolved (this may occur in parallel with the disease activity arm). If fatigue resolves, participants will exit the study at this point. If fatigue persists, further assessments will take place as detailed below.
4. A longitudinal study assessing of dietary and exercise therapies for IBD subjects using a single case study (SCS) design. Participants will also have physical activity levels assessed at recruitment and as needed after active disease/anaemia/nutritional deficiencies have been adequately treated. These assessments will take place on site in St Vincent's University Hospital. If fatigue resolves, participants will exit the study at this point. Those with fatigue despite optimizing nutrition will be offered a physical activity intervention. The time interval between recruitment and resolution of micronutrient deficiencies will vary from patient to patient and so the exact time interval cannot be specified. Each participant will be assessed initially and subsequently assigned a physical activity intervention with a physical therapist designed by the Department of Sports Medicine, University College Dublin.
5. A longitudinal study of acceptance and commitment therapy (ACT) in IBD subjects with psychological disability using a single case study (SCS) design. All patients will undergo psychological assessment as detailed above at recruitment and as needed after active disease/anaemia/nutritional deficiencies have been adequately treated. Those with fatigue and psychological disability will be referred to the IBD psychology service or recruited to a psychological intervention. Participants will receive an intervention with a psychologist from the School of Psychology in University College Dublin to address psychological disability and associated fatigue.
6. A longitudinal study of ACT for IBD subjects with sleep disturbance using a single case study (SCS) design. Patients will have sleep quality assessed at recruitment and as needed after active disease/anaemia/nutritional deficiencies have been adequately treated. Those with sleep disturbance will undergo sleep studies at home both at the start and end of the intervention. This device will be a non-invasive, widely available sleep device worn on the wrist or the patient's index finger for one to three consecutive nights. Participants will be referred to the sleep medicine unit in SVUH if sleep apnea or another diagnosis that requires medical intervention is identified. Otherwise participants will undergo an intervention with a psychologist from the School of Psychology in University College Dublin to address sleep quality.
7. A longitudinal study of probiotics for IBD subjects with fatigue. Participants will have stool samples analysed to assess the microbiome diversity. A twelve-week course of a probiotic which will be taken once daily will then be provided. Stool will be re-assessed at the completion of the intervention.

Each of the four treatment arms will be treated as multiple baseline single case experimental design (SCED). Thus, each participant is treated as an individual study. This type of study provides evidence for the effectiveness of interventions with much fewer participants than group average-based designs such as Randomized Controlled Trials. Standard group-based designs may find an overall treatment benefit on average but may underestimate risks, ineffectiveness, and benefits to the individual.

Each participant will receive a follow up phone call after the intervention is complete, to identify any challenges integrating skills discussed during the interventions. Completion of an online questionnaire will be required at the end of the study period, in order to assess the primary and secondary outcomes.

Any participants with ongoing fatigue will be able to opt to participate in the remaining treatment arms if needed.

Inclusion Criteria:

• Confirmed diagnosis of inflammatory bowel disease

Exclusion Criteria:

• Pregnant women
• Patients unable to consent
• Patients under 18 and over 70 years of age

Individual Participant Data will be anonymised in accordance with EU Data Protection legislation. Anonymised data will be available upon request.