PRIMARY school children's health is at risk because they are unable to get permission from their teacher to go to the toilet, it has been claimed.
A survey, carried out by a HSE public health nurse, found that children are avoiding using the toilets because of worries about where they are located.
Children are also putting off going to the loo over concerns about sanitation and security.
Nurse Maeve Smyth, from Wicklow, was prompted to investigate the issue after school-aged children attending her bed-wetting clinic said they found difficulties following their care plans while at school.
"These children described how they were reluctant to use the school toilets and permission was often denied," she said.
"Significantly, 57pc of the children had difficulties getting permission from the teacher to use the toilet when needed.
"And 34pc of children also intentionally avoided using them. These findings were significantly related to age, location, sanitation and security."
Almost 1,000 school-aged children attending eight Irish primary schools in the east coast were surveyed and 545 children responded. Ms Smyth said prolonged postponing increases the risk of, or exacerbates the problem of, urinary and bowel disorders.
While many children had a positive perception of their school toilets, and used them if they needed to, around 57pc said they experienced difficulties going to the toilet.
A spokesman for the Irish National Teachers Organisation (INTO) said the finding that 34pc of children intentionally avoided using school toilets should be further investigated by the schools concerned.
"Regrettably, sanitation was an issue in some schools due to government neglect of school buildings. While progress has been made in many schools in recent years, there is still a backlog of schools awaiting funding," he said.
"A school board has a duty to ensure that the overall hygiene of a school is of an acceptable standard. But where it is identified that it is of a less than acceptable standard, then the board should be funded by the Department of Education to urgently redress the situation."