Stool Consistency, but Not Frequency, Correlates with Total Gastrointestinal Transit Time in Children

ObjectivesTo evaluate the correlation between stool characteristics (consistency and frequency) and gut transit time in children and to determine whether the Bristol Stool Form Scale is a reliable method of assessing intestinal transit rate in children.Study designFrom March 2011 to March 2012, 44 children (25 boys and 19 girls, mean age 7.8 years) with a diagnosis of functional constipation and 36 healthy, nonconstipated children (17 boys and 19 girls, mean age 7.6 years) were enrolled. All participants maintained a 1-week stool diary, recording the time and date of every bowel movement and stool form, and then completed a validated questionnaire on functional constipation according to Rome III criteria. Whole gut transit time (WGTT) was then assessed using the radiopaque markers test.ResultsThere was a significant correlation between stool form and WGTT in both constipated and nonconstipated children (correlation coefficient −0.84, P < .001). By contrast, there was no correlation between either stool frequency and WGTT or stool frequency and stool form. Multivariate logistic regression analysis, using WGTT as a dependent variable, showed that the sole variable significantly associated with WGTT was stool form (regression coefficient 2.9, OR 18.4, 95% CI 5.4-62.5, P < .001).ConclusionIn this prospective, observational, case-control study, we show that stool form, as measured by the Bristol Stool Form Scale, rather than stool frequency, correlates with WGTT in both constipated and nonconstipated children.