Disorders of sleep and elimination are extremely common in infancy and childhood. At least 10% of all primary school children have sleep disorders, enuresis or encopresis or a combination of these (Graham, 1986). Depending on definitions, younger children have even higher rates of disorder in these domains.

In pre-school children, jactatio capitis nocturna and night terrors are among the most frequent complaints (although not often initially recognized as night terrors) leading to consultation by a whole host of different specialists, including child neurologists and psychiatrists. Sleep walking is also a common sleep disorder, affecting many adolescents and often not properly diagnosed. Many severe sleep disturbances are described simply as ‘frequent night waking’ (Minde et al., 1993). ‘Good’ sleepers wake up as frequently as ‘poor’ sleepers, but they manage to soothe themselves back to sleep without disturbing anyone, at least during the pre-school years. Poor sleepers have more behaviour problems, a more difficult temperament and may have suffered more perinatal insults than those who are regarded as good sleepers.

Enuresis is one of the most common symptoms of early school-age children. It is regarded as an isolated specific developmental disorder which, in itself, should not be regarded as a psychiatric disorder. However, it is often associated with psychiatric disorder, and it often causes emotional and behavioural problems. Encopresis is also a specific developmental disorder. It is associated with severe psychopathology more often than enuresis.