NCT03687814 · University of Michigan
Low FODMAP Plus PEG 3350 for the Treatment of Patients with Irritable Bowel Syndrome-Constipation
What this study is about
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 effectiveness the PEG 3350 + a diet low in fermentable oligo, di, monosaccharides, and polyols (FODMAP) vs. PEG 3350 plus sham diet.
View original scientific description
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.
Interventions
OTHER
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.
OTHER
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 measures
Improvement of abdominal pain as measured by 11-point numerical rating scale
Time frame: during weeks 3 and 4
Compare the proportion of patients with IBS-C on a diet of low FODMAP diet plus PEG 3350 vs. sham diet plus PEG 3350 reporting an improvement of abdominal pain. It is defined 30% reduction in abdominal pain during weeks 3 \& 4 of each diet compared with baseline using an 11-point numerical rating scale (NRS) (0-no pain, 11-intolerable pain). Appropriate between-group statistical comparisons will be conducted.
Who can participate
This study lists these criteria on ClinicalTrials.gov. A study coordinator reviews eligibility during screening — this page does not determine whether you qualify.
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:
- related to defecation
- associated with a change in the frequency of stool (reduction of stools)
- 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
Where
- Ann Arbor, Michigan
Related conditions & keywords
Frequently asked questions
What is a clinical trial?
A clinical trial is a research study that tests new medical treatments, drugs, devices, or procedures to determine their safety and effectiveness. Trials are carefully designed and monitored to protect participants while advancing medical knowledge.
Is it safe to participate?
Clinical trials follow strict safety guidelines and ethical standards. Trials must be reviewed and approved, and participants are closely monitored by medical professionals throughout the study. You can withdraw at any time if you choose.
Will I be compensated?
Many clinical trials offer compensation for your time, travel expenses, and inconvenience. The specific compensation varies by study and will be discussed during the screening process. All study-related medical care is typically provided at no cost to participants.
Will I receive a placebo instead of treatment?
When effective treatment exists, participants typically receive either the standard treatment plus the study intervention, or the standard treatment plus placebo. You would not be denied effective care. Placebos are primarily used when no proven treatment is available, or in addition to standard care. Your trial consent form will clearly explain what treatments you may receive.
Can I leave a trial if I change my mind?
Absolutely. Participation in clinical trials is completely voluntary. You have the right to withdraw from the study at any time, for any reason, without penalty or loss of benefits to which you are otherwise entitled.
How long does a clinical trial last?
Trial duration varies widely depending on the study design and purpose. Some trials last just a few weeks, while others may continue for months or years. The study coordinator will provide specific timeline information during your screening call.
Data: ClinicalTrials.gov · synced Mar 4, 2025 · Source of record for eligibility and locations