Creation and Initial Evaluation of a Stool Form Scale for Children

Objective To develop a pediatric stool form rating scale and determine its interrater reliability, intrarater reliability, and agreement among pediatric gastroenterologists. Study design An ordinal stool scale with 5 categorical stool form types was created on the basis of the Bristol Stool Form Scale, and 32 color 2-dimensional stool photographs were shown to 14 pediatric gastroenterologists. Each gastroenterologist rated the stool form depicted in each photograph with the modified stool scale. Ten gastroenterologists agreed to rerate the stool form depicted in each photograph a minimum of 6 months after the first rating. Results A total of 448 ratings were completed; 430 (94%) of all ratings were within at least 1 category type of the most common (modal) rating for each photograph. Eight (25%) stool photographs had complete agreement among all raters. Interrater and intrarater reliability was high with a single measure intraclass correlation of 0.85 (95% confidence interval: 0.78-0.91; P < .001) and 0.87 (95% confidence interval: 0.81-0.92; P < .001), respectively. Conclusion A modified pediatric Bristol Stool Form Scale provided a high degree of interrater reliability, intrarater reliability, and agreement among pediatric gastroenterologists. (J Pediatr 2010; 157:594-7).