The term was introduced in 1926 by Weissenberg to describe the fecal equivalent of enuresis. The most common reason for functional encopresis is retentive constipation with overflow incontinence. [pedsinreview.aappublications.org]

Encopresis, along with enuresis, is classified as an elimination disorder in the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5 ). [emedicine.medscape.com]

Differences in toileting habits between children with chronic encopresis, asymptomatic siblings, and asymptomatic non-siblings, Journal of Developmental and Behavioral Pediatrics, 1999; 20:145-149. Borowitz SM, Cox DJ, Sutphen JL, Kovatchev B. [med.virginia.edu]

Instead, many behavioral problems develop because of the encopresis, and once the encopresis is treated, many of the behavioral problems may resolve. [med.virginia.edu]