Low FODMAP Plus PEG 3350 for the Treatment of Patients with Irritable Bowel Syndrome-Constipation

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.