A recent study in the Journal of Pediatric Urology indicated that the best time to toilet train a child is between 24 and 32 months of age. Children who did not receive toilet training until after 32 months had more issues with bed wetting, day wetting and urge incontinence. The researchers concluded that the timing of toilet training was more important than the method of the training.
Reference: Robert Wood Johnson Medical School (2010, January 11). Best time to toilet train children pinpointed through research. ScienceDaily. Retrieved January 24, 2010, from http://www.sciencedaily.com /releases/2010/01/100109230611.htm