When to initiate toilet training has been a controversial subject over the centuries. During the first half of the twentieth century opinion leaned towards early training and putting infants on the potty chair at an early age. Since the sixties a more child centered approach has been the dominant trend. The American Academy of Pediatrics recommends that toilet training not begin until the child has attained sufficient muscle control, as indicated by the ability to sit and walk and has sufficient language development to be able to follow instructions. In most children these abilities appear between the ages 18 to 24 months. Yet in recent decades toilet training has often not begun until between 21 and 26 months. (Choby 2008) As a result toilet training is now completed, for a great many children, at a later date than it was in the past.

The reasons for this more relaxed approach to toilet training probably include the widespread use of disposal diapers; the increased number of working mothers for whom toilet training may be easier when the child is older, and a concern that early toilet training might have negative psychological effects. In fact, there is no research to support such concerns and a growing body of research suggests that delayed toilet training may itself lead to later toileting problems.

In a new study just published in the Journal of Developmental Pediatrics, Carol Johnson and her colleagues conducted a comprehensive investigation to explore this issue.(Choby 2008; Johnson 2009). Using data from a longitudinal study in Great Britain, they looked at the records of 8000 Children who had been followed from infancy through the school years on a number of pediatric variables including age of onset of toilet training, and reports of bladder control problems in the early elementary school grades. In evaluating their results, the investigators controlled for other possible influences such as age, sex, and developmental delay. Their conclusion was that, “there is evidence that initiating toilet training after 24 months is associated with problems in attaining and maintaining bladder control after reaching school age.” These finding support similar results from less comprehensive studies.

While it is not clear why the delay in initiating toilet training should present later problems, the authors suggest that stresses encountered when children are older may interfere with the effectiveness of toilet training. In any case the results suggest that for children who are developing normally introducing toilet training between 18 and 24 months of age, is the best protection against the child having toilet problems after reaching school age.

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Choby, B. A. G., S. (2008). "Toilet Training." Amer. Family Physician 78: 1058-1064.

Johnson, C., et al (2009). "A Prospective Study of Age at Initiation of Toilet Training and Subsequent Daytime Bladder Control in School Age Children." Journal of Developmental Pediatrics 30(5): 385-393.