Low-FODMAP Diet for Functional Abdominal Pain Disorders in Children.

Effect of a Low-FODMAP Diet for the Management of Functional Abdominal Pain Disorders in Children

This single-center, randomized, controlled, quadruple-blinded, superiority trial is performed to test the hypothesis that children with IBS and FAP-NOS who receive a low-FODMAP diet will have a lower mean abdominal pain intensity score compared with those who receive a regular diet after 4 weeks of intervention.

Study Overview

• Status: Terminated
• Conditions: Functional Abdominal Pain Disorder
• Intervention / Treatment: Other: Low-FODMAP diet

Detailed Description

Introduction. Evidence from studies in adults documents that fermentable oligosaccharides, disaccharides, monosaccharides, and polyols (FODMAPs) may be triggers of symptoms in individuals with functional abdominal pain disorders. However, in children with FAPDs, there is a need for high-quality evidence regarding the dietary management. We aim to assess the effects of a low-FODMAP diet compared with a regular diet for the management of children with FAPDs.

Methods. In this trial, seventy-four children aged 8 to 18 years with a Functional Abdominal Pain Disorder (Irritable Bowel Syndrome or Functional Abdominal Pain-Not Otherwise Specified), diagnosed according to the Rome IV criteria, will be randomly allocated to receive either a low-FODMAP diet or a regular diet for 4 weeks.A primary outcome will be the percentage of the responders, defined as the participants who have at least 30% improvement in abdominal pain intensity on a Visual Analogue Scale (VAS) during the last week of the trial compared with baseline, that is at least equal to the Reliable Change Index (≥ 25 mm change on VAS).

• Study Type: Interventional
• Enrollment (Actual): 42
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Poland
  • Warsaw, Poland
    • Department of Paediatrics, The Medical University of Warsaw

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 8 years to 18 years (Child, Adult)
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• functional abdominal pain - not otherwise specified (FAP-NOS) or irritable bowel syndrome (IBS) diagnosed according to the Rome IV Criteria,
• baseline average pain intensity at least 30 mm on a 100-mm Visual Analogue Scale,
• feeding via the oral route,
• ability to read and comprehend any employed questionnaires/scales,
• signed informed consent,
• stated availability throughout the study period.

Exclusion Criteria:

• receiving any other intervention/treatment with regard to FAP-NOS or IBS or those who received any other intervention during the last 3 months,
• an organic cause of symptoms or organic gastrointestinal disease,
• chronic illness, receiving medications which affect gastrointestinal motility,
• need for any other dietary management which could make the balancing or compliance with the diet troublesome,
• previously diagnosed carbohydrate intolerance without symptoms of FAPD after implementation of an exclusion diet,
• undernutrition (defined as World Health Organization [WHO] growth charts < -2 SD), decreased growth velocity (sharp decline in growth line), or overweight or obese (> 1 or > 2 SD on the WHO growth charts, respectively),
• unintentional weight loss greater or equal to 5% of subject' body weight within the previous 3 months,
• pregnancy,
• eating disorders,
• prior surgery of the gastrointestinal tract (within last 3 months),
• recurrent or unexplained fever,
• developmental disabilities which impair the ability of the child to understand or communicate.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Quadruple

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Low-FODMAP diet; 37 participants.	Other: Low-FODMAP diet; The low-FODMAP diet will contain the amount of FODMAPs that will not exceed the cut-offs for each FODMAP sugar per serving of food per sitting. Diets will be individually tailored by dietitian and delivered by a catering company (five meals each day).
No Intervention: Regular diet; 37 participants. The regular diet will reflect the habitual FODMAP intake in a normal diet. Diets in both groups will be matched in terms of total energy, fat, protein, carbohydrates and dietary fiber with the usual participant's diet.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in abdominal pain intensity	The primary outcome will be the percentage of the responders, defined as the participants who have at least 30% improvement in abdominal pain intensity on a 100-mm Visual Analogue Scale (VAS) during the last week of the trial compared with baseline, that is at least equal to the Reliable Change Index (≥ 25 mm change on VAS).	At week 1, 2, 3 and 4 from baseline.

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in stool consistency	Bristol Stool Scale is a seven-point scale that distinguish seven pictures of different forms of stool, ranging from the hardest (type 1) to the softest (type 7). At baseline, participants with IBS and a stool consistency score > 5 on the Bristol Stool Scale will be classified as having IBS with predominant diarrhea (IBS-D); if the stool consistency score is < 3, the subjects will be classified as having IBS with predominant constipation (IBS-C). Responders will be subjects with improvement in their average stool consistency during the last week of the trial compared with baseline [≥1 higher Bristol Stool Scale score in case of IBS with predominant constipation, or at least one lower score in case of IBS with predominant diarrhea].	At week 1, 2, 3 and 4 from baseline.
Change in abdominal pain frequency		At week 1, 2, 3 and 4 from baseline.
Change in Gastrointestinal Symptom Rating Scale (GSRS) total score	The GSRS is a 15-item interview-based rating scale. Each item is assessed in a seven-point graded Likert-type scale (one means no symptoms, and seven represents very troublesome symptoms), then total score is calculated.	At week 1, 2, 3 and 4 from baseline.
Change in KIDSCREEN-10 index total score	KIDSCREEN-10 index is a 11-item instrument to assess health-related quality of life (HRQoL). Each item is assessed in a 5-point scale with higher values indicating a higher HRQoL. Total score is calculated.	At week 1, 2, 3 and 4 from baseline.
Change in World Health Organization Five Well-Being Index (WHO-5) total score	The WHO-5 consists of five statements regarding the physical well-being, assessed in a six-point scale (in which zero means at no time, and five represents all of the time). Total raw score is then calculated, ranging from 0 to 25 which is multiplied by four, therefore the final score ranges from 0 (the worst imaginable well-being) to 100 (the best imaginable well-being).	At week 1, 2, 3 and 4 from baseline.
Change in percentage of school attendance associated with IBS symptoms		At week 1, 2, 3 and 4 from baseline.
Change in percentage of parents' work absenteeism associated with IBS symptoms in child		At week 1, 2, 3 and 4 from baseline.
Percentage of compliant participants	The percentage compliance in each group will be calculated. A compliant participant is considered as one who consumes at least 80% of the provided diet. The percent of each meal which the subject consumed (<50%, 50-79% or 80-100%) each day will be reported by participant in a study diary (developed by research team); the additional snacks consumed also will be reported daily (characteristics and amount). Snacks and meals outside the meal plan will be assessed separately.	0-4 weeks.
Percentage of tolerability of the low-FODMAP diet	The tolerability (acceptability) of the diet will be assessed each day using a 100-mm Visual Analogue Scale and reported in the subject diary. This outcome will be reported as a mean for each study group, and as a comparison between groups.	0-4 weeks.
Adverse events	The number of all adverse events and the number of participants reporting adverse events associated with the intervention.	0-4 weeks.
Change in BMI-for-age z-score	The body weight (kg) and standing height (cm) will be measured following standard methods. Body Mass Index (BMI) will be calculated using the standard equation. BMI-for-age z-score will be computed using the WHO AnthroPlus software v1.0.4., then assessed and monitored over time using the WHO growth charts.	At week 2 and 4 from baseline.

Collaborators and Investigators

• Sponsor: Medical University of Warsaw
• Collaborators: Nutricia Foundation

Publications and helpful links

General Publications

• Strozyk A, Horvath A, Muir J, Szajewska H. Effect of a low-FODMAP diet for the management of functional abdominal pain disorders in children: a study protocol for a randomized controlled trial. Nutr J. 2021 Jan 2;20(1):1. doi: 10.1186/s12937-020-00656-3.

Study record dates

Study Major Dates

• Study Start (Actual): April 2, 2023
• Primary Completion (Actual): December 30, 2024
• Study Completion (Actual): December 30, 2024

Study Registration Dates

• First Submitted: August 19, 2020
• First Submitted That Met QC Criteria: August 24, 2020
• First Posted (Actual): August 27, 2020

Study Record Updates

• Last Update Posted (Actual): August 1, 2025
• Last Update Submitted That Met QC Criteria: July 29, 2025
• Last Verified: February 1, 2025

More Information

Terms related to this study

• Keywords: diet; irritable bowel syndrome; functional abdominal pain disorders
• Additional Relevant MeSH Terms: Pain; Neurologic Manifestations; Mental Disorders; Signs and Symptoms, Digestive; Abdominal Pain; Somatoform Disorders
• Other Study ID Numbers: 1W44/5FNUT13/20

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Plan Description: The datasets used and/or generated during this study will be made available after the publication of results, no later than 3 years from the completion of data analysis.
• IPD Sharing Time Frame: Up to 3 years after completion of data analysis.
• IPD Sharing Access Criteria: The datasets will be made available from the contact author upon reasonable request.
• IPD Sharing Supporting Information Type: CSR

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No