Effectiveness of diet, psychological, and exercise therapies for the management of bile acid diarrhoea in adults: A systematic review

Diet therapy (The 8×5 Diet) for adults living with bile acid diarrhoea: protocol for a feasibility randomised controlled trial

INTRODUCTION

A national research priority for people living with bile acid diarrhoea (BAD) is effective treatment options to improve their quality of life. This study aims to evaluate the feasibility of conducting a randomised controlled trial (RCT) of a novel healthy dietary pattern (The 8×5 Diet) to inform a future, larger trial.

METHODS AND ANALYSIS

We plan to enrol 76 UK adults living with BAD and ongoing diarrhoea using self-selection sampling and digital technologies. Eligible participants will be assigned to groups using permuted block randomisation using 1:1 allocation to receive either 8 weeks of usual care or The 8×5 Diet using one-to-one, dietitian counselling via a video-conferencing platform and developed digital resources. Randomisation, consent, recruitment, retention and acceptability will be evaluated using data from the RCT and post-trial interviews conducted with those in the intervention group. Secondary outcome exploratory assessment will include health-related quality of life, symptom relief, diarrhoea, diet quality, nutrient intakes and diet satisfaction.

ETHICS AND DISSEMINATION

Ethical approval was granted by the University of Manchester Research Ethics Committee (2024-19094-33261; V1.7, last updated: 24/02/2025).Findings will be disseminated through peer-reviewed publication, conference presentation and social media.

TRIAL REGISTRATION NUMBER

NCT06259396.

Managing bile acid diarrhea: aspects of contention

INTRODUCTION

Bile acid diarrhea is a common cause of bowel symptoms and often goes unrecognized or misdiagnosed. Many aspects of management remain contentious.

AREAS COVERED

The primary, idiopathic condition should be suspected in people with functional diarrhea or diarrhea-predominant irritable bowel syndrome. Secondary causes include ileal resection, inflammation, and post-cholecystectomy. Diagnostic tests vary globally, being unavailable in many countries, and further refinement of testing strategy is needed. Management is usually long-term symptom control, rather than reversal of the causative factors, which are still being defined. Bile acid sequestrants remain the main drugs used. They are relatively inexpensive, and better-quality data is now available for colesevelam. However, optimal use, including timing and formulation, needs clarification. The GLP-1 receptor agonist, liraglutide, is also effective, although mechanisms of action and whether this effect is common to other class members is unclear. They are more expensive, and availability varies. FXR agonists can also be effective but require further validation. The role of dietary factors in symptom development is a major patient concern, needing more formal studies.

EXPERT OPINION

To build on recent findings, bile acid diarrhea needs further investment into causes, diagnosis and therapy to guide present and future patient care.

Food intolerance related to gastrointestinal symptoms amongst adults living with bile acid diarrhoea: A cross-sectional study

BACKGROUND

The role of food in managing bile acid diarrhoea (BAD) is poorly understood. The present study explored the prevalence of food intolerance amongst adults with BAD.

METHODS

The study comprised a cross-sectional survey of adults with BAD determined by the 75 selenium homotaurocholic acid test (SeHCAT) living in the UK. Participants anonymously completed an online questionnaire on 39 food items. Frequency of food in general affecting BAD symptoms, as well as frequencies of diarrhoea, abdominal pain, bloating, flatulence and consequential food avoidance after food item ingestion, were assessed. Food group avoidance was also assessed.

RESULTS

There were 434 participants who completed the questionnaire between April and May 2021 of whom 80% reported moderate to severe chronic diarrhoea. Food intolerances were reported by 88.0% (95% confidence interval [CI] = 84.6-90.9) of participants. Diarrhoea was reported most frequently after take-away food, fish and chips, creamy sauces, cream and large quantities of fruit (range 41.0%-33.6%). Lowest frequencies were for potato, avocado, mango, watermelon and pear (range 3.7%-7.4%) for the foods listed in the questionnaire. Similar trends were found for abdominal pain, bloating, flatulence and consequential food avoidance. Symptom-triggering within 30 min of ingestion was more prevalence than after 30 min for almost all foods. Food group avoidance was highest for fatty foods (81.2%; 95% CI = 77.8-85.3) followed by dairy (53.9%; 95% CI = 49.1-58.7).

CONCLUSIONS

Perceived food intolerance amongst adults with BAD and persisting diarrhoeal symptoms is high. Important triggers were meals with a higher fat content and higher-fat dairy products. Diets amongst those with persisting diarrhoeal symptoms may be overly restrictive.

Recent developments in diagnosing bile acid diarrhea

INTRODUCTION

Bile acid diarrhea (BAD) commonly causes chronic diarrhea. Symptoms may be mistaken for disorders of gut brain interaction. Due to the lack of widely available diagnostic tests and poor recognition of BAD, there is a delay in diagnosis leading to increased healthcare system burden and decreased patient quality of life.

AREAS COVERED

A thorough review of the literature was conducted using PubMed for articles on the biological functions of bile acids, pathophysiology and management of BAD, but focusing on diagnostic testing including 75SeHCAT retention, 7αC4, FGF-19, fecal bile acids, and single stool tests. This narrative review discusses available modalities focusing on noninvasive stool and serum testing that are more widely available and show good sensitivity and specificity for diagnosis of BAD. 75SeHCAT retention is not available in many countries. Alternative diagnostic tests include total and primary fecal bile acid (BA) excretion in 48-hour collection or a single stool sample, serum7αC4 >46 or 52.5 ng/mL, and combination of single stool and serum 7αC4 ±watery stools (Bristol Stool Form Scale 6-7).

EXPERT OPINION

Given the ease of serum and single stool sample acquisition and diagnostic advances, clinical practice should embrace positive diagnosis, rather than BAS therapeutic trial. BAD needs to be considered in diverse gastrointestinal diseases.

Diagnosis and treatment of post-cholecystectomy diarrhoea

The incidence of cholecystitis is relatively high in developed countries and may usually be attributed to gallstones, the treatment for which involves complete surgical removal of the gallbladder (cholecystectomy). Bile acids produced following cholecystectomy continue to flow into the duodenum but are poorly absorbed by the colon. Excessive bile acids in the colon stimulate mucosal secretion of water and electrolytes leading, in severe cases, to diarrhoea. Bile acid diarrhoea (BAD) is difficult to diagnose, requiring a comprehensive medical history and physical examination in combination with laboratory evaluation. The current work reviews the diagnosis and treatment of BAD following cholecystectomy.