Chapter 48: Elimination Disorders

Elimination disorders represent a class of developmental conditions affecting children's ability to control urinary and fecal functions, characterized by repeated involuntary or intentional passage of urine or stool in inappropriate contexts. Enuresis, the persistent voiding of urine during sleep or waking hours, typically emerges after age five and occurs at least twice weekly for a three month period, though diagnostic criteria emphasize functional impairment and distress rather than frequency alone. The disorder manifests in primary form when continence has never been established, or secondary form when a child regresses following a period of dryness, with nocturnal presentation being most prevalent. Etiological factors encompass neurodevelopmental immaturity of the central nervous system's role in bladder regulation, abnormal sleep-wake arousal mechanisms, genetic predisposition evidenced by increased familial clustering, and psychosocial stressors that may precipitate or exacerbate symptoms. Treatment approaches integrate behavioral methods including alarm conditioning, fluid management protocols, and retention control exercises alongside pharmacological interventions such as desmopressin, tricyclic antidepressants, and anticholinergic medications. Encopresis involves repeated fecal soiling beyond age four in the absence of organic medical pathology and divides into two phenotypic presentations: retentive form associated with chronic constipation and overflow incontinence reflecting attempted stool withholding, and nonretentive form linked to oppositional behaviors and reduced toilet compliance. Clinical presentation frequently includes painful defecation, fecal avoidance, social shame, and significant family dysfunction. Comorbid psychiatric conditions including attention deficit hyperactivity disorder, oppositional defiant disorder, and conduct disturbances appear at elevated rates. Management requires multimodal intervention combining psychoeducation, structured defecation schedules, bowel management through osmotic laxatives or stool softeners, positive reinforcement systems, and when indicated, individual psychotherapy or biofeedback techniques. Both conditions demonstrate favorable prognosis with consistent intervention, though chronic presentations require sustained therapeutic engagement and family support.