Toilet training typically occurs after the second birthday. Some children show interest by age 2, but others may not be ready until months later. The average age for girls to be toilet trained is 29 months and for boys it is 31 months, and 98% of children are trained by 36 months (Boyse & Fitzgerald, 2010). The child’s age is not as important as his/her physical and emotional readiness. If started too early, it might take longer to train a child.
Muscle Development Needed for Toilet Training
Parents are usually aware that as soon as the baby is fed milk or formula the diaper needs to be changed almost immediately. This is an involuntary elimination process that occurs because a baby’s digestive system has not yet fully matured. Just as in adults, urine fills the bladder and is released through the urethra, and bowel movements fill the large intestine and is expelled via the rectum. Babies do not yet have control of the sphincter muscles that keep the rectum and bladder closed, so as fluid fills the bladder the sphincter muscles automatically relax, and bowel or urination movement occurs. This is an involuntary process and a baby is unable to consciously delay the elimination. Parents may place the baby on the toilet at the right time, but the baby cannot deliberately wait to use the potty, therefore cannot be fully potty-trained. 19
According to The Mayo Clinic (2016b) the following questions can help parents determine if a child is ready for toilet training:
Does your child seem interested in the potty chair or toilet, or in wearing underwear?
Can your child understand and follow basic directions?
Does your child tell you through words, facial expressions or posture when he or she needs to go?
Does your child stay dry for periods of two hours or longer during the day?
Does your child complain about wet or dirty diapers?
Can your child pull down his or her pants and pull them up again?
Can your child sit on and rise from a potty chair?
If a child resists being trained or it is not successful after a few weeks, it is best to take a break and try again when they show more significant interest in the process. Most children master daytime bladder control first, typically within two to three months of consistent toilet training. However, nap and nighttime training might take months or even years.
Elimination Disorders
Some children experience elimination disorders including:
enuresis - the repeated voiding of urine into bed or clothes (involuntary or intentional) after age 5
encopresis - the repeated passage of feces into inappropriate places (involuntary or intentional).
The prevalence of enuresis is 5%-10% for 5 year-olds, 3%-5% for 10 year-olds and approximately 1% for those 15 years of age or older. Around 1% of 5 year- olds have encopresis, and it is more common in males than females. These are diagnosed by a medical professional and may require treatment. 20