Testing a new diet for managing bile acid diarrhoea

The 8x5 Diet for Bile Acid Diarrhoea: A Feasibility Randomised Controlled Trial

Not applicable Interventional University of Manchester · NCT06259396

This study is testing a new diet called The 8x5 Diet to see if it can help adults with bile acid diarrhoea manage their symptoms better than their usual diet.

Quick facts

PhaseNot applicable
Study typeInterventional
Enrollment76 (estimated)
Ages18 Years and up
SexAll
SponsorUniversity of Manchester Academic / other
Locations1 site (Manchester, Greater Manchester)
Trial IDNCT06259396 on ClinicalTrials.gov

What this trial studies

This study aims to assess the feasibility of a dietary intervention called The 8x5 Diet for adults suffering from bile acid diarrhoea, a condition that often leads to chronic watery diarrhoea despite medication. The trial will recruit 76 participants from across the United Kingdom, who will be randomly assigned to either continue their usual diet or follow The 8x5 Diet for 8 weeks, with guidance from a specialist dietitian. The primary goal is to evaluate the practicality of conducting a larger randomized controlled trial by examining aspects such as consent, recruitment, randomization, and retention rates.

Who should consider this trial

Good fit: Ideal candidates are adults aged 18 and older living in the UK with a confirmed diagnosis of bile acid diarrhoea and ongoing symptoms despite treatment.

Not a fit: Patients who are pregnant, breastfeeding, or planning a pregnancy in the next six months will not benefit from this study.

Why it matters

Potential benefit: If successful, this dietary intervention could provide a new, effective management option for patients with bile acid diarrhoea who do not respond well to medication.

How similar studies have performed: While dietary interventions for gastrointestinal disorders have been explored, this specific approach has not been previously tested in a randomized controlled trial format.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

* Age ≥ 18 years, of any ethnic group, living in the United Kingdom and not planning to move home for the next three months
* Self-reported diagnosis of bile acid diarrhoea that was confirmed by 7-day SeHCAT testing
* Self-reported ongoing chronic diarrhoea despite use of appropriate medication
* Able to participate in either diet group with the intention to remain in the group to which they were assigned for the 8 week study period
* Body mass index ≥20 kg m-2
* Able to converse in English (or via their carer, without assistance from an interpreter) using a computer/laptop, smart phone, or tablet
* Able to provide informed written consent
* Able to provide the address of their general practioner so that the research team can inform them of their participation.

Exclusion Criteria:

* Unable to provide self-reported written confirmation that their diagnosis of bile acid diarrhoea was by SeHCAT testing
* Pregnant/breastfeeding/planning a pregnancy in the next six months
* Inflammatory bowel disease, previous or current microscopic colitis, or other serious morbidities such as liver disease, pancreatic disease, AIDS/HIV, radiotherapy for cancer, assessed at screening via patient self-report
* Diarrhoea that is inadequately active: \<3 stools per day or \<1 watery stool (Bristol Stool Form types 6-7) per day as the mean of one week
* Currently participating in another research study or has taken part in the previous 3 months
* If taking insulin, metformin (other than slow-release), anti-obesity medication, or using commercially available formulated supplements to replace meals in previous three months
* Use of antibiotics in the previous four weeks

Medically necessary dietary exclusions or issues deemed incompatible with the trial:

* Food allergies, other than oral allergy syndrome/pollen-food syndrome
* Exclusion of gluten (i.e. coeliac disease), lactose, biogenic amines, or any other dietary exclusion assessed as unsuitable as screening by the trial team. This includes if the participant knows they would refuse to eat: starchy foods, fruit and vegetables, protein-rich foods, or dairy and alternatives (e.g. following a ketogenic diet)
* An eating disorder or disordered eating which is active or in the last 12 months
* Alcohol or drug abuse, or self-harm, or depression, or suicide ideation in the last 12 months
* Shift worker
* If unwilling to keep a weighed 7-day food diary

Where this trial is running

Manchester, Greater Manchester

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions Bile Acid Diarrheadiet interventionnutritionfeasibilitydiarrhoeaadults
Last reviewed 2026-06-13 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.