Other Specified Elimination Disorder 359
Prevalence
It is estimated that approximately 1% of 5-year-olds have encopresis, and the disorder is
more common in males than in females.
Development and Course
Encopresis is not diagnosed until a child has re ached a chronological ag e of at least 4 years
(or for children with developmental delays, a mental age of at least 4 years). Inadequate,
inconsistent toilet training and psychosocial st ress (e.g., entering school, the birth of a sib-
ling) may be predisposing factors. Two types of  course have been described: a “primary”
type, in which the individual has never established fecal continence, and a “secondary”
type, in which the disturbance develops after a period of established fecal continence. En-
copresis can persist, with interm ittent exacerbations, for years.
Risk and Prognostic Factors
Genetic and physiological. Painful defecation can lead to co nstipation and a cycle of with-
holding behaviors that make encopresis more likely. Use of some medications (e.g., anti-
convulsants, cough suppressants) may increase constipation and make encopresis more
likely.
Diagnostic Markers
In addition to physical examination, gastrointestinal imaging (e.g., abdominal radiograph)
may be informative to assess retained stool an d gas in the colon. Additional tests, such as
barium enema and anorectal ma nography, may be used to help exclude other medical
conditions, such as Hirschsprung’s disease.
Differential Diagnosis
A diagnosis of encopresis in the presence of  another medical condition is appropriate only
if the mechanism involves constipation that cannot be explained by other medical condi-