Plain English Summary
Background and study aims
Irritable Bowel Syndrome (IBS) is a common condition with symptoms causing around 1 in 10 people to seek help from their GP at some point in their lives. It is a combination of abdominal discomfort or pain and altered bowel habits. Depending on the stool consistency, IBS can be classified as IBS with diarrhoea (IBS-D), IBS with constipation (IBS-C), or mixed IBS (IBS-M). IBS is often a chronic condition that can significantly impair quality of life and cause absence from work and school. The emergence of new drugs for IBS has been slow and there is a need for new treatment alternatives, including drug-free treatments, which are easy to use and can safely be used in different types of patients, including in children and pregnant women. Currently available drug-free treatments include Enterosgel®, which is an intestinal adsorbent that has been approved for use in patients with IBS-D and is available over-the-counter in the UK. It is an orally consumed gel-like product classified as a medical device, which has been shown to adsorb harmful substances like bacterial toxins in the gut. There have been studies suggesting that Enterosgel® and other intestinal adsorbents can improve diarrhoea, bloating and abdominal pain in patients with IBS-D. However, larger studies are needed to further investigate the potential benefits of Enterosgel® in the treatment of IBS-D. This study aims to recruit 430 participants with IBS-D. The goal is to investigate whether Enterosgel® can improve IBS-D symptoms, including diarrhoea and abdominal pain. In addition, the study aims to investigate the impact of this treatment on the quality of life, work productivity and activity and general health. The safety and tolerability of Enterosgel® in this condition will also be evaluated.
Who can participate?
Adults aged 18 and over who have been diagnosed with IBS-D and have diarrhoea symptoms
What does the study involve?
The study involves in total five visits over 26 weeks. At each visit and at given time points between the visits, the participants complete questionnaires asking about their IBS symptoms, quality of life, work productivity and activity and general health. In addition, the participants are asked to complete a study diary throughout the study to record their symptoms and treatment use. The diary is available as a mobile phone application. Those participants who are not able to use the electronic version receive a paper diary. The diary should be completed daily for the first 18 weeks and weekly for the last 8 weeks. At the first visit (week 0), potential participants are provided with the study diary to record their diarrhoea symptoms for 2 weeks. Those who had sufficient diarrhoea symptoms over this period are eligible to take part in the study and are randomly allocated to one of two treatment groups at the second visit (week 2). The first group receive dummy treatment and the second group receive Enterosgel® for 8 weeks. Neither the participants nor the research team know which treatment the participant receives. After 8 weeks, the participants attend the third visit (week 10) and all participants are given Enterosgel® for the next 8 weeks. This time, the participants are informed about the treatment they receive and are advised to take the treatment whenever they have diarrhoea symptoms. After 8 weeks of treatment with Enterosgel®, the participants attend the fourth study visit (week 18) and return to standard-of-care. A final visit takes place 8 weeks later (week 26).
What are the possible benefits and risks of participating?
To allow all patients to try Enterosgel®, this study includes an 8-week period where all participants receive it. Some participants may find that Enterosgel® helps with their IBS symptoms while others might not experience any benefit. The aim of this study is to evaluate what proportion of participants can benefit from this treatment, and what the benefits are. In the future, this information can be helpful to the patients and healthcare professionals when they are considering different treatment alternatives. Enterosgel® has been available in some countries for 30 years and is commonly used as a treatment for gastrointestinal conditions, including acute diarrhoea and IBS-D. According to the manufacturer, possible known side effects are nausea and constipation. Enterosgel® is completely excreted from the gut and does not get absorbed into the blood circulation.
Where is the study run from?
This study will be conducted at about 30 medical practices and secondary care centres in the UK. In addition to the participating research sites, the study is advertised through local pharmacies and through an IBS research register called ContactME-IBS (https://www.contactme-ibs.co.uk)
When is the study starting and how long is it expected to run for?
March 2017 to December 2019
Who is funding the study?
Enteromed Ltd (UK)
Who is the main contact?
Dr Carol Howell
Randomised, double-blind, placebo controlled multi-centre study to assess the efficacy, tolerability and safety of Enterosgel® in the treatment of Irritable Bowel Syndrome with Diarrhoea (IBS-D) in adults (RELIEVE IBS-D)
The hypothesis is that Enterosgel® is superior compared with placebo in terms of patient reported outcomes for stool consistency and abdominal pain, in patients with IBS-D.
Not provided at time of registration
Randomised double-blind placebo-controlled multi-centre trial
Primary study design
Secondary study design
Randomised controlled trial
Patient information sheet
Irritable Bowel Syndrome with diarrhoea (IBS-D)
Using a centralised computer-based randomisation tool, patients will be randomised 1:1 to receive intestinal adsorbent Enterosgel® or placebo. The patients will receive blinded study treatment for 8 weeks according to study-specific dosage instructions, which allow adjusting the dosage based on IBS symptoms. The treatment is provided in 90g tubes, each containing a single treatment dose. The Enterosgel® tubes contain 22.5g Enterosgel® pre-diluted in water. The placebo tubes contain water with chalk added to mimic the appearance and consistency of Enterosgel®. Treatments are taken orally up to 6 doses per day, depending on the symptoms.
After 8 weeks of blinded treatment, all patients will receive open-label Enterosgel® treatment for 8 weeks to take if they experience diarrhoea.
Following the open-label treatment period, all patients will return to standard-of-care and will be followed up for 8 weeks.
Primary outcome measures
Percentage of patients defined as responders for abdominal pain and stool consistency based on daily study diary data, during at least 4 weeks in the 8-week blinded treatment period, where:
1. An Abdominal Pain Intensity Weekly Responder is defined as a patient who experiences a decrease in the weekly average abdominal pain score of at least 30 percent compared with baseline. The weekly average abdominal pain score is derived by scoring the worst pain experienced each day and taking the average for one week
2. A Stool Consistency Weekly Responder is defined as a patient who experiences a 50 percent or greater reduction in the number of days per week with at least one stool that has a consistency of Bristol Stool Form Scale (BSFS) Type 6 or 7 compared with baseline
Secondary outcome measures
Double-blind treatment phase and open-label treatment phase:
1. Stool frequency based on daily study diary data; mean over 8 weeks and the last 4 weeks of each treatment period
2. Stool consistency assessed as average number of days/week with Bristol Stool Scale type >5 based on daily study diary data and percentage of responders over 8 weeks and the last 4 weeks of each treatment period
3. Abdominal pain based on daily study diary data; mean on a VAS scale from 0 to 10 over 8 weeks and the last 4 weeks, percentage of responders over 8 weeks and the last 4 weeks of each treatment period
4. Bloating based on weekly study diary data; mean weekly score on a numerical scale from 0 to 6 over 8 weeks and the last 4 weeks of each treatment period
5. Urgency based on weekly study diary data; mean weekly score on a numerical scale from 0 to 6 over 8 weeks and the last 4 weeks of each treatment period
6. Percentage of patients reporting adequate relief of global IBS symptoms based on weekly study diary data weekly from baseline until week 8 of each treatment period
7. Irritable Bowel Syndrome Severity Scoring System (IBS-SSS) score weekly from baseline until week 8 of each treatment period
8. Irritable Bowel Syndrome Quality of Life (IBS-QOL) score every 4 weeks from baseline until week 8 of each treatment period
9. Patient Health Questionnaire-12 Somatic Symptom scale (PHQ-12 SS) score to measure severity of somatic symptoms excluding gastrointestinal symptoms every 4 weeks from baseline until week 8 of each treatment period
10. IBS-related Work Productivity and Activity Impairment (WPAI:IBS) score; weekly from baseline until week 8 of each treatment period
11. Use of rescue medication, i.e. loperamide, based on weekly study diary data; number of days over each 8 weeks of treatment
12. Adverse events over each 8 weeks of treatment
1. Satisfaction with bowel symptoms based on weekly study diary data; mean weekly score on a numerical scale from 0 to 6, over 8 weeks
2. Satisfaction with abdominal pain based on weekly study diary data; mean weekly score on a numerical scale from 0 to 6, over 8 weeks
3. Loperamide use based on weekly study diary data; mean number of days per week over 8 weeks
4. Irritable Bowel Syndrome Severity Scoring System (IBS-SSS) score at baseline and 8 weeks
5. Patient Health Questionnaire-12 Somatic Symptom scale (PHQ-12 SS) score to measure severity of somatic symptoms excluding gastrointestinal symptoms at baseline and 8 weeks
6. Irritable Bowel Syndrome Quality of Life (IBS-QOL) score at baseline and 8 weeks
7. IBS-related Work Productivity and Activity Impairment (WPAI:IBS) score at baseline and 8 weeks
8. Percentage of patients who maintained treatment benefit over 8 weeks after cessation of treatment based on weekly study diary data over 8 weeks
Overall trial start date
Overall trial end date
Participant inclusion criteria
1. Irritable Bowel Syndrome with diarrhoea (IBS-D) according to Rome IV criteria
2. Negative calprotectin test or adequate exclusion of Inflammatory Bowel Disease (IBD)
3. Aged 18+
4. Considered suitable to take part in the study by the consenting physician
Target number of participants
Participant exclusion criteria
1. Loose stools (BSFS 6 or 7) on less than 3 days during the last 14 days before Baseline
3. Organic gastrointestinal disorder
4. Celiac disease (existing diagnosis)
5. Lactose malabsorption (existing diagnosis)
6. Bile acid malabsorption (existing diagnosis)
7. Bowel cancer
8. Previous use of Enterosgel®
10. Diary completed on at least 11 of 14 days (≥75%) during the screening period
Recruitment start date
Recruitment end date
Countries of recruitment
Trial participating centre
University Hospital of North Durham
85 Great Portland Street
Funding Body Type
Funding Body Subtype
Results and Publications
Publication and dissemination plan
Study results will be submitted for presentation(s) at gastroenterology conference(s) and for publication in international peer-reviewed scientific journal(s). Results will be disseminated to the patients and the public through the study website. Protocol will be made available immediately following publication with no end date.
IPD sharing statement
After publication, individual anonymised participant data that underlie the results reported in the publication will be available to researchers upon request from Dr Carol Howell at Enteromed Ltd. Participants have provided their consent for the sharing of anonymised data for research purposes.
Intention to publish date
Participant level data
Available on request
Results - basic reporting