35 Voiding Disorders and Incontinence
Voiding disorders and incontinence are common disorders of micturition that are presented to the physician. They occur more frequently in elderly persons; currently, about 15% of Americans are older than 65 years. Although voiding disorders and incontinence are common problems, patients are often reluctant to bring them to their healthcare providers’ attention.
Lower urinary tract (LUT) dysfunction causes lower urinary tract symptoms (LUTS). Newer terminology divides LUTS into several groups: voiding (obstructive), storage (filling/irritative), postmicturition symptoms, overactive bladder syndrome, and bladder outlet obstruction.
Voiding symptoms usually caused by LUT obstruction include intermittent or split stream, slow stream, terminal dribbling, and straining. Storage symptoms include daytime frequency, nocturia, urgency, and incontinence. Postmicturition symptoms include the sensation of incomplete emptying and postmicturition dribbling. The latter suggests benign prostatic obstruction but could be considered a form of urinary incontinence due to a weakness in the pelvic floor muscles.
Voiding dysfunction is the rule rather than the exception in elderly men. Signs and symptoms of benign prostatic hypertrophy (BPH) have been found in about 70% of elderly male patients. Incontinence is so common in women that many patients consider it normal. Decreased bladder capacity and involuntary bladder contractions have been found in as many as 20% of continent elderly persons. About 10% to 20% of community-dwelling elderly patients have urinary incontinence severe enough to be considered a social or health problem. Large-scale studies have reported that one third of people older than 60 years occasionally experience an involuntary loss of urine. An even larger percentage of hospitalized and institutionalized elderly patients are troubled with 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.
Enuresis is common until about 4 to 5 years of age. In most children with voiding disturbances, no anatomic or neurologic disease is causing their enuresis. UTI should be suspected in children of all ages if they have secondary enuresis or an unexplained fever lasting 48 hours or more.
Voiding dysfunction is common in elderly men. The amount of prostatic enlargement does not necessarily correlate with the symptoms of prostatism. Some young men found not to have prostatic enlargement on rectal examination have symptoms of prostatism, the so-called trapped prostate.
Incontinence is more common in women than men. It occurs more frequently in multiparous and menopausal women, in confused patients, and in those with limited mobility. Age-related changes in bladder function include decreased capacity, increased residual urine, increased involuntary bladder contractions (detrusor muscle instability), and increased nocturnal urine production. Incontinence has been reported in 26% of women during their reproductive years, but in the postmenopausal years the incidence is 30% to 40%. Patients with neurologic disorders, such as multiple sclerosis and spinal cord injury, may present with symptoms of neurogenic bladder leading to overflow incontinence.
The symptoms of prostatism can be divided into two categories: obstructive symptoms (e.g., weak stream, abdominal straining, hesitancy, intermittency of stream, incomplete emptying, terminal dribbling) and storage symptoms (e.g., daytime frequency, nocturia, urgency). Some patients have symptoms of prostatic enlargement and also have symptoms related to unstable detrusor muscle contractions. The symptoms of BPH often wax and wane spontaneously, probably because of changes in dynamic factors, which include bladder tone, bladder neck obstruction, and tone in the prostate and prostatic capsule.
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.
In children the symptoms of functional voiding disorders include increased or decreased frequency of urination, urgency, dysuria, nocturnal enuresis, daytime wetting after toilet training is completed, fever, abdominal pain, perineal pain, constipation, and encopresis. The severity and presence of symptoms vary so much that children with the same voiding disorder frequently have different symptoms. The most common symptoms are increased frequency and urgency. Dysuria may be caused by bladder dysfunction without infection, although UTI should always be suspected.
Nocturia, the presence of two or more nighttime voidings, increases with age. Studies report a 55% prevalence in men older than 70 years and a 79% prevalence in men older than 80 years. The incidences are similar in men and women, although some studies suggest a slightly higher rate in men. It is one of the most common causes of disturbed sleep.