Gluten-free Diet in Irritable Bowel Syndrome

Study Overview
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Brief Summary
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To evaluate the effects of a gluten-free diet in irritable bowel syndrome.

Detailed Description
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Irritable bowel syndrome with diarrhoea (IBS-D) is commonly encountered in primary and secondary-care practice. There are various triggers including diet. There is a growing number of people taking a gluten-free diet (GFD) of their own volition even in the absence of coeliac disease (CD). The investigators aim to assess whether a GFD could be of benefit to patients with IBS-D, previously naive to the effects of gluten and in whom CD has been excluded as per normal duodenal biopsies. The investigators will also assess whether certain factors may predict a clinical responder such as the presence or absence of at-risk coeliac serology.

Official Title
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Assessing the Clinical Response to a Gluten Free Diet in Patients With Diarrhoea Predominant Irritable Bowel Syndrome, in Whom Overt Coeliac Disease Has Been Excluded

Conditions
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Irritable Bowel Syndrome

Intervention / Treatment
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* Dietary Supplement: Gluten-free diet


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patients aged 16 years or over Patients fulfilling ROME III symptom based criteria for IBS-D but do not have coeliac disease Exclusion Criteria: Patients diagnosed with coeliac disease Patients already on a gluten-free diet Patients initially referred with self-reported gluten sensitivity Patients with organic conditions that can mimic IBS-D such as idiopathic bile acid diarrhoea, pancreatic insufficiency, microscopic colitis, and inflammatory bowel disease

Ages Eligible for Study
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Minimum Age: 16 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Non-Randomized
Intervention Model: Parallel Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: At-risk serology<br>Gluten-free diet | Dietary Supplement: Gluten-free diet<br>* Patients with IBS-D will commence a gluten-free diet for 6 weeks following dietetic input. They will be informed they do not have coeliac disease. They will however be blinded to whether or not they have any markers of at-risk serology. They will self-complete validated questionnaires over 6 weeks. Any subjects who opt to continue with a gluten-free diet thereafter of their own volition will be kept under observation as per routine clinical care.<br>|
| Active Comparator: Not at-risk serology<br>Gluten-free diet | Dietary Supplement: Gluten-free diet<br>* Patients with IBS-D will commence a gluten-free diet for 6 weeks following dietetic input. They will be informed they do not have coeliac disease. They will however be blinded to whether or not they have any markers of at-risk serology. They will self-complete validated questionnaires over 6 weeks. Any subjects who opt to continue with a gluten-free diet thereafter of their own volition will be kept under observation as per routine clinical care.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Irritable Bowel Syndrome Symptom Severity Scores. This validated questionaire will be self-completed at baseline and at week 6. The investigators will compare the changes in scores over this time point. |  | 6 weeks | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Hospital Anxiety and Depression scores. This validated questionaire will be self-completed at baseline and at week 6. The investigators will compare the changes in scores over this time point. |  | 6 weeks | 
| Fatigue Impact Scores. This validated questionaire will be self-completed at baseline and at week 6. The investigators will compare the changes in scores over this time point. |  | 6 weeks | 
| Short-form 36 Quality of Life Scores. This validated questionaire will be self-completed at baseline and at week 6. The investigators will compare the changes in scores over this time point. |  | 6 weeks | 
| Assess whether patients opt to continue with a GFD of their own volition | At the end of the six-week GFD trial period, patients will be asked whether or not they plan to continue with a GFD of their own volition. This will be assessed by a yes/no answer. Those who choose to do so will now be followed-up under routine clinical care over the next 1-2 years. This will allow the investigators to assess whether symptom-remission is maintained by using the same questionnaires mentioned in outcomes 1 to 4. It will also allow the investigators to monitor well-being in the form of body-mass index and serum haematinics (vitamin B12, folate, ferritin, albumin, haemoglobin). | 1-2 years |