Condition category
Digestive System
Date applied
Date assigned
Last edited
Retrospectively registered
Overall trial status
Recruitment status
No longer recruiting

Plain English Summary

Background and study aims
Inflammatory bowel disease (IBD) is a chronic relapsing remitting disease characterised by inflammation of the gut. Between 35% and 57% of patients with IBD in remission also report a range of gut symptoms similar to those experienced in functional bowel disorders, including irritable bowel syndrome (IBS), such as abdominal pain, bloating and diarrhoea. These symptoms are not associated with underlying inflammation of the disease, but may result in reduced quality of life.
There is growing evidence for the use of a diet low in fermentable carbohydrates (the low FODMAP diet) for the management of functional gut symptoms (FGS) in patients with IBS. There is early evidence for the use of this diet in patients with IBD who have FGS during inactive disease; however, there are no studies published in this area.
This study aims to find out if IBD patients are sensitive to individual fermentable dietary carbohydrates (FODMAPs). Patients will receive drinks containing common dietary carbohydrates and symptom response will be compared with a placebo (dummy) challenge.

Who can participate?
Male and female adult IBD patients who have experienced a sustained improvement in their symptoms whilst following the low FODMAP diet, recruited from outpatient clinics at Guy’s and St Thomas’ NHS Foundation Trust, London, UK.

What does the study involve?
Over a period of about six months patients will be invited to take part in the study. At an initial visit before the start of the study demographic and disease characteristics and details regarding FGS will be collected. Measurements will include disease activity scores, bowel habits diary, diet history, and stool and blood markers of inflammation. Participants will continue on the low FODMAP diet throughout the study.
Participants will then be assigned to a random sequence of four carbohydrate test drinks. Participants will take one measure of powdered carbohydrate mixed into water with breakfast or in the morning within a specified time frame. The drinks will be consumed once daily for three days and a daily gut symptom and stool diary will be kept to monitor symptoms. In addition, a daily adherence diary will be kept. After the three test days participants will be instructed on following a four-day washout phase in which they will continue the diet with no test drinks. This phase is to ensure that symptoms have returned to as they were before the start of the intervention, before starting the next test. This will be repeated for each of the four test drinks.
Once a participant has completed all four tests, they will attend a final visit for an end of study blood and stool sample to recheck inflammation. Any adverse events will also be recorded.

What are the possible benefits and risks of participating?
The main benefit of participating in the study is that patients will learn which carbohydrates they are most sensitive to, enabling appropriate dietary changes to be made to help them manage their symptoms effectively. The low FODMAP diet is well tolerated, is not known to have any negative effects and is routinely used in clinical practice.
Risk to patient safety is not expected. The main burden to participants will be continuing a strict low FODMAP diet for the duration of the trial, completing gut symptom and stool diaries, providing two blood and stool samples, and consuming the test drinks. The test drinks may induce symptoms that cause abdominal discomfort and/or a change in bowel habit; however, the quantities of carbohydrates used in the test drinks will be similar to those consumed in their previous ‘normal diet’ and symptoms are not expected to be greater than those experienced by patients before commencing the diet. There are no safety concerns of consuming these dietary carbohydrates.
Taking blood samples is a routine procedure used frequently in clinical practice. Participants may experience mild pain or discomfort during the procedure and may notice a small bruise or mild soreness for a few days afterwards. The procedure will be performed by an experienced and trained phlebotomist.

Where is the study run from?
The study will be run from King’s College London and Guy’s and St Thomas’ NHS Foundation Trust gastroenterology outpatient clinics, UK.

When is the study starting and how long is it expected to run for?
Recruitment is expected to start at the beginning of March 2014 and will continue until the end of September 2014.

Who is funding the study?
King's College London, UK.

Who is the main contact?
Professor Kevin Whelan, Professor of Dietetics
Dr Peter Irving, Consultant in Gastroenterology,
Alexis Prince,

Trial website

Contact information



Primary contact

Prof Kevin Whelan


Contact details

King's College London
School of Medicine
Diabetes and Nutritional Sciences Division
4.06 Franklin Wilkins Building
150 Stamford Street
United Kingdom

Additional identifiers

EudraCT number number

Protocol/serial number


Study information

Scientific title

Fermentable dietary carbohydrates as triggers of functional gut symptoms in patients with inflammatory bowel disease: a randomised controlled crossover trial


Study hypothesis

It is hypothesised that, in patients with inactive inflammatory bowel disease who have reported an improvement in functional gut symptoms (FGS) following a low fermentable carbohydrate diet, rechallenge with individual fermentable dietary carbohydrates (FODMAPs) will induce FGS compared with a placebo, glucose.

Ethics approval

NRES Committee London - Camberwell St Giles, 16/01/2014, ref. 13/LO/1878

Study design

Double-blinded placebo-controlled crossover rechallenge trial

Primary study design


Secondary study design

Randomised controlled trial

Trial setting


Trial type


Patient information sheet

Not available in web format, please use the contact details below to request a patient information sheet


Inflammatory bowel disease (Crohn’s disease and ulcerative colitis)


Current interventions as of 23/04/2014:
Each participant will complete all four dietary carbohydrate Fermentable Oligo-Di-Monosaccharides and Polyols (FODMAP) challenges in a random order:

1. Test: Fermentable carbohydrate drink containing 12 grams of fructans
2. Test: Fermentable carbohydrate drink containing 6 grams of galactooligosaccharides
3. Test: Fermentable carbohydrate drink containing 6 grams of sorbitol
4. Control: Fermentable carbohydrate drink containing 12 grams of glucose

Previous interventions:
Each participant will complete all four dietary carbohydrate Fermentable Oligo-Di-Monosaccharides and Polyols (FODMAP) challenges in a random order:

1. Test: Fermentable carbohydrate drink containing 12 grams of fructans
2. Test: Fermentable carbohydrate drink containing 6 grams of galactooligosaccharides
3. Test: Fermentable carbohydrate drink containing 2 grams of sorbitol
4. Control: Fermentable carbohydrate drink containing 12 grams of glucose

Intervention type



Not Applicable

Drug names

Primary outcome measures

To find out whether FGS are adequately controlled following rechallenge with individual FODMAPs compared with a placebo, glucose. This will be measured by a Global Symptom Question “Do you currently have satisfactory relief of your gut symptoms?” with a 'yes' or 'no' response. This will be measured at baseline, for 3 days during each test and on day 4 of the washout phase to ensure symptoms have returned to baseline.

Secondary outcome measures

1. Ratings and mean scores for individual symptoms during each test phase, which will be measured by the Gastrointestinal Symptom Rating Scale. This will be measured at baseline, for 3 days during each test and on day 4 of the washout phase.
2. Faecal calprotectin and serum CRP levels, measures of inflammation, will be measured at baseline and at the end of the trial.

Overall trial start date


Overall trial end date


Reason abandoned


Participant inclusion criteria

1. Men and women aged 18 years or over
2. Individuals able to give informed consent
3. Diagnosis of IBD confirmed by standard clinical, histological and radiological criteria
4. Diagnosis of IBD for duration of at least 6 months. IBD in remission as defined by physician global assessment, patient report and two markers of absence of inflammation: C-reactive protein (CRP) <10mg/l and faecal calprotectin <250μg/g.
5. Stable medications (see exclusion criteria), no recent surgery (see exclusion criteria) and stable symptoms for at least 2 months
6. Diagnosis of functional bowel disorder as defined by Rome III criteria (IBS or functional bloating or functional diarrhoea or functional abdominal pain syndrome) with marked and sustained improvement of these symptoms on the low fermentable carbohydrate diet
7. A willingness to participate

Participant type


Age group




Target number of participants


Participant exclusion criteria

1. Patients with active IBD
2. Recent use of the following treatments: antibiotics or prebiotics in the preceding 4 weeks, non steroidal anti-inflammatory drugs (NSAIDs) during the preceding week.
3. Currently taking steroids
4. Recent changes in dose to the following treatments: azathioprine, 6-mercaptopurine, methotrexate or alpha tumor necrosis factor (alpha-TNF) agents during the preceding 12 weeks, oral 5-aminosalicylic acid (5-ASA) or steroids during the preceding 4 weeks
5. Previous panproctocolectomy, pure perianal disease or short bowel syndrome
6. Stenotic disease
7. Sepsis or fever
8. Diabetes or coeliac disease (by serology and/or duodenal biopsy)
9. Other concomitant serious comorbidity e.g. significant hepatic, renal, endocrine, respiratory, neurological or cardiovascular disease
10. Pregnancy or lactation
11. Taking any medications with the potential to influence gastrointestinal symptoms unless taking a long term stable dose that is unlikely to change or stop during the trial

Recruitment start date


Recruitment end date



Countries of recruitment

United Kingdom

Trial participating centre

King's College London, School of Medicine
United Kingdom

Sponsor information


King's College London (UK)

Sponsor details

c/o Mr Keith Brennan
Room 1.8 Hodgkin Building
Guy's Campus
United Kingdom

Sponsor type




Funder type


Funder name

King's College London (UK)

Alternative name(s)

Funding Body Type

Funding Body Subtype


Results and Publications

Publication and dissemination plan

Not provided at time of registration

Intention to publish date

Participant level data

Not provided at time of registration

Results - basic reporting

Publication summary

Publication citations

Additional files

Editorial Notes