Halmos EP, et al. – Physicians designed this study to compare subjective and objective assessment of fecal characteristics in irritable bowel syndrome (IBS) patients. They found major disparities between patients’ stool descriptions and objective features of constipation and diarrhea. For accurate IBS subtyping, patient–reported bowel habits required more interrogation. Varying FODMAP (Fermentable Oligosaccharides, Disaccharides, Monosaccharides And Polyols) or gluten content of the diet was not associated with a consistent change in fecal water content (FWC).

Methods

• The physicians interrogated data from two interventional dietary trials with varying FODMAP (Fermentable Oligosaccharides, Disaccharides, Monosaccharides And Polyols) or gluten content.
• Using a visual analog scale, subjects rated their dissatisfaction with stool consistency daily during the interventions.
• At the end of each intervention, subjects collected stools.
• According to the King's Stool Chart (KSC), each stool was scored.
• They measured fecal water content (FWC) on pooled feces by freeze drying, with diarrhea defined as ≥78%.

Results

• The physicians studied 70 IBS (Rome III) and 8 healthy subjects.
• During the most symptomatic diet, each subject's self-rating of stool consistency was almost double that of their least.
• With changes in FWC and KSC, degree of dissatisfaction with stool consistency correlated poorly.
• IBS subtype correlated poorly to objective measures of stool consistency.
• On objective measures, 60% of IBS-D subjects had diarrhea.
• 85% with IBS-C had hard and formed stools but 3 patients met the criteria for diarrhea.
• On FWC and KSC, 1 healthy subject had diarrhea, and 6 had hard, formed stools.
• They observed no differences in FWC when subjects consumed differing amounts of FODMAPs or gluten (all P > .200).