Definition	Constipation is characterized by infrequent bowel evacuations; hard, small feces; or difficult or painful defecation. The frequency of bowel evacuation varies from person to person.1 Encopresis is defined as involuntary bowel movements in inappropriate places at least once a month for three months or more in children four years and older.2
Incidence/Prevalence	Constipation with or without encopresis is common in children. It accounts for 3 percent of consultations to pediatric outpatient clinics and 25 percent of pediatric gastroenterology consultations in the United States.3 Encopresis has been reported in 2 percent of children at school entry. The peak incidence is at two to four years of age.
Etiology/Risk Factors	No cause is discovered in 90 to 95 percent of children with constipation. Low fiber intake and a family history of constipation may be associated factors.4 Psychosocial factors are often suspected, although most children with constipation are developmentally normal.3 Chronic constipation can lead to progressive fecal retention, distension of the rectum, and loss of sensory and motor function. Organic causes for constipation are uncommon but include Hirschsprung's disease (one per 5,000 births; male-to-female ratio of 4:1; constipation invariably present from birth), cystic fibrosis, anorectal physiologic abnormalities, anal fissures, constipating drugs, dehydrating metabolic conditions, and other forms of malabsorption.3
Prognosis	Childhood constipation can be difficult to treat and often requires prolonged support, explanation, and medical treatment. In one long-term follow-up study of children presenting before five years of age, 50 percent recovered within one year and 65 to 70 percent recovered within two years; the remainder required laxatives for daily bowel movements or continued to soil for years.3 It is not known what proportion continue to have problems into adult life, although adults presenting with megarectum or megacolon often have a history of bowel problems from childhood.
Clinical Aims	To remove fecal impaction and to restore a bowel habit in which stools are soft and passed without discomfort.
Clinical Outcomes	Number of defecations per week; number of episodes of soiling per month; gut transit time as measured by timing the passage of radio-opaque pellets, which may be ingested within a gelatin capsule; use of laxatives.