Potty Training Before Age 2 Linked to Increased Risk of Later Wetting Problems, Research Shows
Children who start toilet training before age 2 have a three
times higher risk of developing daytime wetting problems later, according to
new research at Wake Forest Baptist
“Parents who train their children early to meet preschool deadlines, to save
landfills from diapers or because they think toddlers are easier to train
should know there can be serious repercussions,” says lead author Steve Hodges,
M.D., an associate professor of pediatric urology at Wake Forest Baptist.
The study, reported online in Research and Reports in
Urology, involved 112
children ages 3 to 10. About half were seen in the urology department for
daytime wetting or urinary urgency/frequency. They were compared to a group
seen in a general pediatric clinic and pediatric emergency room who had no
history of dysfunctional voiding.
A questionnaire was used to gather information on the age toilet training was
initiated and the presence of daytime voiding dysfunction. Patients were
grouped into three categories of potty training: early (before age 2), normal
(between 2 and 3) and late (after age 3) training. There were 38 early, 64
normal and 10 late trainers.
percent of the early trainers had daytime wetting. They had a 3.37 times
increased risk of daytime wetness as compared to the normal group. The researchers believe early
trainers are more prone to subsequent voiding dysfunction because they are more
apt to “hold” their stool or urine. “When children hold stool, it backs up in the
rectum,” Hodges explained. “The enlarged rectum presses against the bladder,
reducing its capacity and causing the nerves feeding the bladder to go
In fact, in
the current study, early trainers were three times more likely to complain of
constipation than normal trainers. “Almost all of the children who had wetting
also had constipation,” Hodges noted.
Younger children also are more apt to delay
peeing, behavior that can lead to bladder contractions and reduced bladder
capacity. “Research has demonstrated that bladder growth continues in children
up to the point of toilet training,” said Hodges. “Uninhibited voiding in
diapers is likely beneficial to bladder development. In my practice, it’s often
the children who trained earliest and most easily who end up with the most
severe voiding problems.”
The study also found that among the 10 children
who trained after age 3, seven had daytime wetting problems, and these same
seven also were constipated. The three late trainers who did not have wetting
problems were not constipated.
“This does not mean late potty training causes dysfunctional voiding,” Hodges
explained. “It means that when kids train late, it’s very likely because they
are already constipated, which makes toilet training extremely difficult.
Parents whose 3- or 4-year-olds have trouble training are often blamed for
‘waiting too long,’ but our data suggest waiting isn’t the problem — instead it’s likely constipation.”
Hodges said constipation in children often goes
undiagnosed because pediatricians, following International Children’s
Continence Society guidelines, simply ask parents whether their children’s
bowel movements are infrequent and if stool consistency is hard.
“These questions fail to detect enlarged rectums that compromise bladder
capacity,” said Hodges. “Children can have daily bowel movements and still be
constipated. Extra-large stools and stools shaped like pellets or logs are far
more indicative of constipation than bowel-movement frequency. But an X-ray
will provide a definitive diagnosis.”
Hodges advises parents to initiate toilet
training when children show signs of readiness — and have absolutely no signs
of constipation — rather than at a certain age.
“There is nothing magic about the age of
two,” said Hodges. “If parents opt to train early or late and are meticulous
about making sure children void on a regular schedule and monitor them for
signs of constipation, I suspect the incidence of voiding dysfunction would
Hodges said his study
is the first to consider constipation status along with age of potty training.
Other studies have found late trainers are more prone to dysfunctional voiding
and concluded there’s a “magic window” before age 3 during which children can
avoid problems. “But these studies never considered whether the late trainers
were constipated when parents tried to train them,” Hodges said.
Hodges has written a book for consumers that covers this and other toileting issues
Co-authors were Kyle A. Richards, M.D., Ilya
Gorbachinsky, M.D., and L. Spencer Krane, M.D., of Wake Forest Baptist.
Media Relations Contacts: