Toilet training (or potty training) is the process of teaching children to use the toilet rather than diapers for excretion. The ability to use the toilet is a development skill that a child cannot master until they are ready both mentally and physically, thus it cannot be rushed. Children are often toilet trained between the ages of 12 months and 3 years, but each child starts and completes their training at different times. Girls are usually toilet trained before boys of the same age, but a boy could be toilet trained at two while a girl not until age four.
Psychologist Sigmund Freud and many after him believed that training to use the toilet was one of the most formative events of the human psyche, introducing to the child that social imperatives can take precedence over bodily desires.
This article will cover several topics including when is a child ready to toilet train, how to start toilet-training, and some parent's delay of toilet training in recent years.
When to start toilet training
How to start toilet training
Delay of toilet training
A rising trend in recent years is for parents to delay toilet training. While the average age for a child used to be 18 months, the average age has recently gone to three to four years with some children as old as seven still wearing and using diapers.  This delay may be caused by the change in attitude from nurseries or as the result of parent's laziness. Modern diaper technology may be to blame as well. In disposable diapers, the fabric that contacts the skin simply wicks away any dampness, causing the child to not feel any discomfort and simply carry on with their activities. 
The decision to keep children in diapers past infancy has been the subject of much controversy. Family psychologist John Rosemond claims it is a "slap to the intelligence of a human being that one would allow a baby to continue soiling and wetting himself past age 2."  Pediatrician T. Berry Brazelton on the other hand, says "Don't rush your toddler into toilet training or let anyone else tell you it's time. It's got to be his choice," and supports Pampers Size 6 diapers for older children. Many pediatricians have seen more children with toilet training issues in recent years, these include withholding of urine and stool, chronic constipation, and older children still wetting and soiling themselves.
This recent trend of later toilet training has also fed the multi-billion dollar diaper industry. Diaper-producers such as Procter & Gamble and Kimberly-Clark have created diapers in even larger sizes designed for toddlers as well as disposable "training pants".
- Rogers, Lois (17-06-2008) Absolutely potty! How children are still wearing nappies to SCHOOL - with dire risks to their health, Daily Mail.
- Delayed Potty Training Issues