Soluble and Osmotic Fibre (SOLOS) Diet for Constipation (SOLOS)

The Soluble and Osmotic Fibre (SOLOS) Diet for Functional Bowel Disorders With Constipation

This research aims to study the dual effectiveness of incorporating soluble fibre and osmotic carbohydrates (SOLOS), with or without restricting fructans and GOS, and present novel findings in managing GI symptoms in patients with functional bowel disorders with constipation. These findings may also support researchers and clinicians in shaping new dietary approaches in the management of general constipation symptoms.

Study Overview

• Status: Not yet recruiting
• Conditions: Constipation; Diet Modification; Constipation-predominant Irritable Bowel Syndrome; Diet Therapy; Constipation - Functional; Constipation Chronic Idiopathic; Constipation, Signs and Symptoms, Digestive; Dietary Fiber; Dietary Fibers; Constipation Predominant Irritable Bowel Syndrome; Dietary and Nutritional Therapies; Constipation-predominant IBS (IBS-C); Diet, Food and Nutrition; Constipation-predominant Irritable Bowel Syndrome (IBS-C)
• Intervention / Treatment: Other: Diet

Detailed Description

Aims: This retrospective clinical audit study aims to evaluate the effectiveness of dietary advice promoting increased intake of soluble fibre and poorly absorbed (osmotic) carbohydrates, with or without restriction of fructans and galacto-oligosaccharides (GOS), on adult patients (18-70 years old) with functional bowel disorders with constipation from the UK by comparing to baseline scores for severity and frequency of gastrointestinal symptoms and stool output.

Hypothesis: The dietary advice promoting increased intake of soluble fibre and osmotic sugars will produce a significant change from baseline in gastrointestinal symptoms and stool output in adult patients (18-70 years old) with functional bowel disorders with constipation from the UK.

Methodology: The study population will include all patients who have consulted with the Principal Investigator, a specialist gastroenterology dietitian between January 2021 and December 2025. All patients who have met the inclusion criteria will then form the research sample. Eligible subjects' data and study variables will be extracted from patient letters and clinical management records without direct patient contact. These study variables include the frequency and severity of the patients' symptoms at their initial appointment and follow-up appointment if available. Anthropometric data such as height and weight will also be obtained. The compiled data will then be analysed by conducting statistical tests, specifically the paired t-test, which will produce descriptive statistics that will interpret the effectiveness of the SOLOS diet on patients with functional bowel disorders with constipation.

Applications: To date, there has not been any study studying the dual effects of soluble fibre and osmotic carbohydrates consumption on alleviating constipation-related symptoms in patients with functional bowel disorders with constipation. Therefore, this research aims to present novel findings that can advance existing dietary management of functional bowel disorders with constipation. These results are expected to deepen understanding and research in food manufacturing and clinical nutrition.

• Study Type: Observational
• Enrollment (Estimated): 180

Contacts and Locations

• Study Contact: Name: Bridgette J Wilson, Dr; Phone Number: +65 82629995; Email: bridgette.wilson@singaporetech.edu.sg

Study Locations

• Singapore
  • Singapore
    • Singapore, Singapore, Singapore, 828608
      • Singapore Institute of Technology
      • Contact: Bridgette J Wilson, Dr; Phone Number: +65 82629995; Email: bridgette.wilson@singaporetech.edu.sg

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

• Sampling Method: Non-Probability Sample

Study Population

Adult patients (18-70 years old) with functional bowel disorders with constipation from the UK, seen by a specialist dietitian (Principal Investigator)

Description

Inclusion Criteria:

• Presented with symptoms of FC, IBS-C, or SIBO-C
• Were aged 18 to 70 years old. (Research focus is on adult patients, excluding older adults and children)
• Date of baseline (first) and follow-up appointments ranged from January 2021 to December 2025
• Did not attend follow-up appointments (Data would be treated as "intention to treat" and data points were carried forward for conservative analysis).

Exclusion Criteria:

• Had no history of constipation-related symptoms (Does not relate to research question's population or outcome)
• Started treatment before January 2021
• Were not due for follow-up before the end of December 2025
• Symptom and stool data inadequately recorded

Study Plan

How is the study designed?

Number of groups / cohorts

2

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
Patients with Functional Constipation	Other: Diet; Dietary advice combining increased intake of dietary sources of soluble fibres and osmotic sugars in improving constipation symptoms.; Other Names: soluble fibre and osmotic carbohydrates diet; soluble fibre and osmotic carbohydrates (SOLOS) diet; SOLOS diet
Patients with IBS-C or SIBO-C	Other: Diet; Dietary advice combining increased intake of dietary sources of soluble fibres and osmotic sugars in improving constipation symptoms.; Other Names: soluble fibre and osmotic carbohydrates diet; soluble fibre and osmotic carbohydrates (SOLOS) diet; SOLOS diet

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Stool frequency	Frequency of stool output per week	January 2021 to December 2025
Stool form	Bristol Stool Form Scale	January 2021 to December 2025
Gastrointestinal Symptom Frequency	Frequency of gastrointestinal symptom in a week, recorded as number of days out of 7 the symptom occurred over the past week.	January 2021 to December 2025
Gastrointestinal Symptom Severity	Severity of symptoms in a week scored using Gastrointestinal Symptom Rating Scale (GSRS). Scores range from 0 (absent) to 3 (severe).	January 2021 to December 2025

Collaborators and Investigators

• Sponsor: Singapore Institute of Technology
• Investigators: Principal Investigator: Bridgette J Wilson, Dr, Singapore Institute of Technology

Study record dates

Study Major Dates

• Study Start (Estimated): February 2, 2026
• Primary Completion (Estimated): March 1, 2027
• Study Completion (Estimated): March 1, 2027

Study Registration Dates

• First Submitted: January 28, 2026
• First Submitted That Met QC Criteria: January 28, 2026
• First Posted (Actual): February 5, 2026

Study Record Updates

• Last Update Posted (Actual): February 6, 2026
• Last Update Submitted That Met QC Criteria: February 4, 2026
• Last Verified: February 1, 2026

More Information

Terms related to this study

• Keywords: Constipation; Soluble fiber; Functional constipation; Constipation-predominant irritable bowel syndrome (IBS-C); osmotic sugar
• Additional Relevant MeSH Terms: Signs and Symptoms, Digestive; Pathological Conditions, Signs and Symptoms; Signs and Symptoms; Constipation; Diet, Food, and Nutrition; Physiological Phenomena; Nutritional Physiological Phenomena; Diet
• Other Study ID Numbers: RECAS-0723-IRB

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No