Using the Bristol Stool Scale and Parental Report of Stool Consistency as Part of the Rome III Criteria for Functional Constipation in Infants and Toddlers

Objectives To evaluate among parents of infants and toddlers the agreement between parental report and the Bristol Stool Scale (BSS) in assessing stool consistency and the effect of both methods on determining the prevalence of functional constipation (FC) according to the Rome III criteria. Study design Parents of children <= 48 months of age who were seen for a well-child visit completed a questionnaire about their child's bowel habits during the previous month. Cohen kappa coefficient (k) was used to measure intrarater agreement between parental report of stool consistency ("hard," "normal," "soft/mucous/liquid") and the BSS (types 1-2, hard; types 3-5, normal; types 6-7, loose/liquid). The prevalence of FC was assessed based on the questionnaire according to the Rome III criteria, comparing both methods of stool consistency assessment. Results Parents of 1095 children (median age, 15 months; range, 1-48) were included. Only fair agreement existed between the 2 methods of stool consistency assessment (k = 0.335; P < .001). According to the Rome III criteria, using parental report the prevalence of FC was 20.5% and using the BSS the prevalence was 20.9% (P = .87). The agreement between these 2 methods for assessing the prevalence of FC was excellent (k = 0.95; P < .001). Conclusions Only fair agreement exists between the BSS and parental report of stool consistency among parents of infants and toddlers. Different methods of stool consistency assessment did not result in a difference in the prevalence of FC.