Infant stool form scale: development and results.

Objective: To develop an infant stool scale describing consistency, amount, and color and test its usefulness by assessing the differences between term and preterm infants, between breastfed and formula fed infants and examining interobserver and intraobserver variability.
Study Design: Information about gestational age, postnatal age, and feeding type was collected in relation to each photograph taken. An infant stool form scale describing consistency (4-point scale), amount (4-point scale), and color (6 categories) was developed. All photographs were scored twice with the newly developed scale to assess interobserver and intraobserver variability. Consensus database describing stool characteristics was developed.
Results: A total of 555 photographs of infant stools were analyzed; 60 (11%) of the infants studied were term, and 495 (89%) were born prematurely. No differences were found between preterm and term infants. Breastfed infants had smaller amounts of stools compared with formula-fed infants (P< .001). The interobserver weighed kappa value (95% CI) was good for consistency and amount; the simple kappa value was good for color. For observers I and II intraobserver kappa values were excellent.
Conclusion: This "Amsterdam" stool form scale is useful to assess defecation patterns in both premature and term born infants.