Sequential acquisition of toilet-training skills: a descriptive study of gender and age differences in normal children.

Objective: To compare the ages, by gender, at which normally developing children acquire individual toilet-training skills and to describe the typical sequence by which children achieve complete toileting success.

Methods: A longitudinal survey was conducted of a cohort of children who were 15 to 42 months of age and attending 4 pediatric practices in the Milwaukee area (2 inner city and 2 suburban) from 1995 through 1997. Parents completed background surveys, and each child's development was assessed using the Bayley Scales of Infant Development II.