35 Voiding Disorders and Incontinence
Childhood enuresis (bed-wetting), whether primary or secondary, should be considered a symptom rather than a specific diagnosis. Most cases represent primary enuresis, a maturational delay that is occasionally familial. Secondary enuresis occurs when a child who has been continent demonstrates enuresis. Secondary enuresis may result from emotional stress (e.g., birth of a sibling, beginning school) or a urinary tract infection (UTI). In these children, bacteriuria may cause uninhibited bladder contractions. Most children with nocturnal or daytime incontinence (99%) have not an anatomic abnormality but rather a disturbance in urodynamics, such as bladder instability.
Nature of Symptoms
An abrupt onset of symptoms of stress or urge incontinence suggests infection. The gradual onset of symptoms of stress incontinence, particularly after menopause or oophorectomy, suggests estrogen deficiency. When the amount of urine leakage is small to moderate and coincides with increased abdominal pressure, stress incontinence is probable. Large amounts of urine and incontinence associated with the sensation of a full bladder suggest an overactive bladder with detrusor muscle instability. This precipitous loss of large quantities of urine unrelated to increased abdominal pressure suggests involuntary detrusor contractions, as does incontinence associated with an extreme desire to void because of pain, inflammation, or a sense of impending micturition. The symptoms of an overactive bladder (frequency, nocturia, and urgency) can occur with or without incontinence. Moderate dripping suggests a partially incompetent outlet, overflow, or congenital or acquired anomalies. Having the patient keep a bladder diary over a few days, noting leakage frequency, voiding intervals, activity or sensation with leakage, and amount and type of fluid intake, is often helpful in determining the cause of incontinence.