Parents are too busy to potty train their children early enough - not recognizing the strain the delay puts on their bladders and bowels, a survey suggests.
A survey of early years staff in the UK by charity ERIC and the National Day Nurseries Association (NDNA) revealed 68% of them feel that over the past five years children were being potty trained at a later age.
Almost half (43%) of the 202 early years practitioners questioned felt it was down to parents putting it off because they are too busy or at work too long.
The nursery practitioners said parents needed more support, and 92% believed toilet training should be a shared responsibility between nursery and home.
To support this, NDNA and children's bowel and bladder charity, ERIC, have developed a potty training policy and training for nursery staff.
They are also preparing resources for practitioners and families that will focus on what they need to know - such as spotting the signs of a child being toilet ready and steps to achieve potty training success.
A nursery owner from West Midlands said: "Parents are busy and it has lifestyle impacts. It's about being consistent and showing them early on about what a potty is, but the morning routine is a busy time for parents to be able to do this.
"They rely on nursery to do this, but the potty should be the first place a child goes once they wake up to understand the morning bowel routine."
Purnima Tanuku, chief executive of NDNA, said: "It's clear that parents and nursery practitioners need to work more closely together to benefit children so no child goes to school unable to use the toilet properly. "
Juliette Randall, chief executive of ERIC, said: "It's good news that so many settings include potty training as part of their age two progress review, however only 53% of respondents actually have a potty training policy in place.
"Critically, the survey showed there is little or no recognition of the relationship between successful potty training and healthy bladders and bowels.
"Constipation is the most common bowel problem in children affecting up to 30% of all children and particularly common among pre-school children.
"It can have a huge impact on potty training, yet only 16% include how to identify and manage constipation in their policies."
The survey suggests that 70% of early years practitioners have received no guidance in how to potty train.
It also indicates that many look online for information and support (27%).