Health Education Delivery Methods for a Low Fermentable Carbohydrate Diet in Patients With Functional Bowel Disorders

• Compliance rates to the diet[ Time Frame: Follow-up visit (week 4) ]
  Compliance rates to the diet within the study groups assessed via a 7day food and drink diary
• Satisfaction over the education delivery methods received[ Time Frame: Baseline (Day 0) and Follow-up visit (week 4) ]
  Satisfaction over the education methods and diet, assessed via 5-point Likert scales (1=Strongly Agree, 2=Agree, 3=Neutral, 4=Disagree, 5=Strongly Disagree)
• Appropriateness of the education methods received in each study group[ Time Frame: Baseline (Day 0) and Follow-up visit (week 4) ]
  Perceived appropriateness of the education methods, assessed via 5-point Likert scales (1=Strongly Agree, 2=Agree, 3=Neutral, 4=Disagree, 5=Strongly Disagree)
• Perceived fit of the education delivery methods within the NHS[ Time Frame: Follow-up visit (week 4) ]
  Assessed via a 5-point Likert scale (1=Strongly Agree, 2=Agree, 3=Neutral, 4=Disagree, 5=Strongly Disagree)
• Willingness of participants being assigned to the study groups using a multiple choice questionnaire.[ Time Frame: Follow-up visit (week 4) ]
  Assessed via a question on whether they would like to have been randomised to a different group (Yes/No)
• Gastrointestinal symptom severity[ Time Frame: Baseline (Day 0) and Follow-up visit (week 4) ]
  Validated Irritable Bowel Syndrome-Severity Scoring System (IBS-SSS) questionnaire. The questionnaire includes four VAS items evaluating abdominal pain frequency and intensity, abdominal distension, satisfaction with bowel habit, and quality of life. Scores are then added up; scoring allows categorisation of patients into mild (75-174), moderate (175-300) and severe (>300) cases, with a maximum achievable severity score of 500 points. A minimal clinically important difference of a 50-point reduction in score allows meaningful interpretation of score change over time.
• Health-related quality of life in irritable bowel syndrome[ Time Frame: Baseline (Day 0) and Follow-up visit (week 4) ]
  Validated Irritable Bowel Syndrome-Quality of Life (IBS-QoL) questionnaire. Each item utilises a 5-point Likert response scale, which is transformed to a 0-100 point scale and subscale scores are then calculated (dysphoria, interference with activity, body image, health worry, food avoidance, social reaction, sexual, relationships). A total score can be calculated by summing the subscale scores. A score of 100 denotes maximum QOL for subscales and the total score.
• Gastrointestinal symptoms experienced[ Time Frame: Baseline and follow-up visitBaseline (Day 0) and Follow-up visit (week 4) ]
  Assessed using Gastrointestinal Symptom Rating Scale (GSRS). Gastrointestinal symptoms (Abdominal discomfort or pain, Heartburn, Acid reflux, nausea, abdominal gurgling, bloating, burping, flatulence, constipation, diarrhoea, loos stools, hard stools, urgency, incomplete evacuation, tiredness, overall symptoms) are rated in a 4-point Likert scale (0=Absent, 1=Mild, 2=Moderate, 3=Severe). Descriptive and inferential statistical results are presented for each individual symptom seperately.
• Adequate relief of symptoms[ Time Frame: Baseline (Day 0) and Follow-up visit (week 4) ]
  Assessed using the "adequate relief of IBS symptoms" question (IBS-AR). The outcome is dischotomous (Yes/No) and counts/percentages that have reported adequate relief ("Yes") will be presented.
• Estimates of the parameters required for calculation of the sample size for a future larger study[ Time Frame: Screening (Week -1), Baseline (Day 0) and Follow-up visit (week 4) ]
  The results of this study will be used to inform the sample size calculation of a future larger study if needed. The outcome that will be used for the sample size calculation depends on the which the primary outcome of the future study will be. The mean and standard deviation generated from this study will be used for the sample size of the future trial.

There is evidence for the use of a diet low in short chain fermentable carbohydrates (low FODMAP diet) in the management of functional gut symptoms, such as abdominal pain and bloating. However, the provision of advice on the low FODMAP diet can be challenging due to limited resources and the need for a dietitian with expertise in the low FODMAP diet. The aim of this study is to assess the feasibility in terms of recruitment and retention in planning a future trial. The purpose of the future trial will be to investigate the clinical and cost effectiveness, as well as the acceptability of different education methods of the low FODMAP diet for the treatment of IBS. To date, there are no studies on the implementation of the low FOMDAP diet using a mobile app or leaflets in the education of the low FODMAP diet. Therefore, a feasibility study design was chosen in order to obtain key data on recruitment and retention rates at each study group.

• Other: Health education delivery methods

• Experimental: Booklets
  Health education delivery method: Booklet. Patients will be given 2 leaflets on the low FOMDAP diet produced by the Department of Nutrition and Dietetic in Guy's & St Thomas' NHS Foundation Trust, and the Diabetes and Nutritional Sciences Division at King's College London. These booklets have been produced by dietitians and are commonly used in clinical practice across the UK.
• Experimental: Mobile application
  Health education delivery method: Mobile application. Patients will be asked to download an application on their mobile phones or tablets. This application has been produced by dietitians from the Department of Nutrition and Dietetic in Guy's & St Thomas' NHS Foundation Trust, and the Diabetes and Nutritional Sciences Division at King's College London.
• Active Comparator: One to one consultation with dietitian
  Health education delivery method:One-to-one consultation with dietitian. Patients will attend a clinic visit for a one-to-one consultation with a dietitian. As per current clinical practice, the initial visit will last for 1 hour. During the visit, tailored information on the low FOMDAP diet will be given to match patients' individual needs. During the visit, either the leaflets (used in group 1) or the application (used in group 2) will be used to facilitate the visit. The choice of using the leaflets or the app during the visit will be based on the dietitian's judgment based on the patients' needs.