Toilet training can be increasingly difficult for parents of children who have certain developmental, behavioral or medical disorders. Children with autism, fetal alcohol spectrum disorder, oppositional defiant disorder, or attention deficit hyperactivity disorder may not be motivated to complete toilet training, may have difficulty appropriately responding to associated social reinforcements, or may have sensory sensitivities which make using the toilet unpleasant.Children may have a range of physical issues related to the genitourinary system, that could require medical assessment and surgical or pharmacological intervention to ensure successful toilet training. Those with cerebral palsy may face a unique set of challenges related to bladder and bowel control, and those with visual or auditory problems may require adaptations in the parental approach to training to compensate, in addition to therapy or adaptive equipment.Stool toileting refusal occurs when a child that has been toilet trained to urinate, refuses to use the toilet to defecate for a period lasting at least one month. This may affect as many as 22% of children and can result in constipation or pain during elimination. It usually resolves without the need for intervention. Children may exhibit stool withholding, or attempts to avoid defecation all together. This can also result in constipation. Some children will hide their stool, which may be done out of embarrassment or fear, and is more likely to be associated with both toileting refusal and withholding.Although some complications may increase the time needed to achieve successful bladder and bowel control, most children can be toilet trained nonetheless.: 3 : 162  Physiological causes of failure in toilet training are rare, as is the need for medical intervention. In most cases, children who struggle with training are most likely not yet ready.In a 2014 survey of UK schools, primary school teachers and educational staff reported observing an increasing number of otherwise healthy schoolchildren who were not toilet trained. 15% of respondents reported that they had observed healthy children aged 5-7 wearing diapers to school in the past year. 5% reported the same for children aged 7-11. A health worker with the Kent Community Health NHS Foundation Trust said that she knew of medically healthy adolescents as old as 15 with toilet training issues. Commentators attributed the issue to parents being too busy to teach their children basic skills.