Recruiting

Low FODMAP with PEG 3350

Sponsor:

University of Michigan

Code:

NCT03687814

Conditions

Irritable Bowel Syndrome Characterized by Constipation

Eligibility Criteria

Sex: All

Age: 18+

Healthy Volunteers: Not accepted

Interventions

Low FODMAP diet/PEG 3350

sham diet/PEG 3350

Study Details

Brief summary:

Consecutive patients with Irritable Bowel Syndrome with Constipation (IBS-C) will be recruited from the outpatient clinics of the University of Michigan Health System. Eligible patients will be asked to participate in a study that will test the efficacy the PEG 3350 + a diet low in fermentable oligo, di, monosaccharides, and polyols (FODMAP) vs. PEG 3350 plus sham diet. Blinding dietary advice trials is challenging and therefore the sham diet was based on the criteria set forth by Staudacher et al. which emphasizes that the diet must give the impression that is the true intervention diet with similar restrictions, modifications, and time intensity without impacting the intake of essential nutrients, fiber, and FODMAPs. An example of the sham diet's carbohydrates includes: apples, bananas, and pears, and wheat. Oranges, raspberries, strawberries and rice would not be allowed. Additionally, the physicians analyzing the data will be blinded as to which group the patients were randomized.

Conditions

Irritable Bowel Syndrome Characterized by Constipation

Study ID

NCT03687814

Start date

Nov 8, 2018

Status verified date

Feb, 2025

Completion date

Jan, 2026

Anticipated

Primary completion date

Jan, 2026

Anticipated

Eligibility Criteria

Eligibility Criteria

Sex: All

Age: 18+

Healthy Volunteers: Not accepted

Inclusion Criteria:

1. Subjects aged 18 and older meeting the Rome IV criteria for IBS-C\*:

• Recurrent abdominal pain, on average, at least 1 day/week in the last 3 months, associated with two or more of the following:

1. related to defecation
2. associated with a change in the frequency of stool (reduction of stools)
3. associated with a change in the form of stool (hard or lumpy stools) AND >25% hard stools and <25% loose stools \* Criteria fulfilled for the last 3 months

Exclusion Criteria:

  • any other IBS subtype other than IBS-C
  • >3 spontaneous bowel movements during the last 7 days of run-in
  • Have cognitive dysfunction or unable to understand or provide written informed consent
  • Pregnancy (evaluated by self-report)
  • Comorbid medical problems that may affect gastrointestinal transit or motility:
  • Inflammatory bowel disease
  • Extra-intestinal disease known to affect the gastrointestinal system (i.e., scleroderma, unstable thyroid disease, etc.)
  • Severe renal or hepatic disease
  • Previous abdominal surgery other than appendectomy, cholecystectomy, and gynecologic/urologic surgery if performed more than six months prior to enrollment
  • Previous treatment with the low FODMAP diet under a dietician guidance
  • Concurrent medications not permitted including probiotics, antibiotics, prescription or over-the-counter medication for IBS, and narcotics
  • New antidepressant use (less than 3 months on stable dose)
  • Active participation in another form of dietary therapy

Study Design

Enrollment

78 participants

Anticipated

Allocation

Randomized

Intervention Model

Parallel Assignment

Primary purpose

Treatment

Interventions and Outcome Measures

Arms

experimental: Low FODMAP diet plus PEG 3350

Subjects will follow a low FODMAP diet and will take PEG 3350 (Miralax).

sham comparator: Sham diet plus PEG 3350

Subjects will follow a sham diet and will take PEG 3350 (Miralax).

Interventions

Low FODMAP diet/PEG 3350

Subjects will follow a low FODMAP diet and will take PEG 3350 (Miralax) at 17.7 g (single dose) daily for 4 weeks.

sham diet/PEG 3350

Subjects will follow a sham diet and will take PEG 3350 (Miralax) at 17.7 g (single dose) daily for 4 weeks.

Primary outcome measure

  • Improvement of abdominal pain as measured by 11-point numerical rating scale [ Time Frame: during weeks 3 and 4 ]

Central Contacts and Locations

Central contacts

Stacy Menees, MD, MS

734-232-3739sbartnik@med.umich.edu

Amy Liu, BS

734-647-4794liuyalie@med.umich.edu

Locations

University of Michigan

Recruiting

Ann Arbor, Michigan, United States, 48109

More Information

Sponsor

University of Michigan

Last update posted

Mar 4, 2025

Last verified

Feb, 2025

Trial information was received from ClinicalTrials.gov and was last updated on 2026-09-10. This information was provided to ClinicalTrials.gov by University of Michigan on 2025-03-04.