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Diurnal Enuresis

1997; American Academy of Pediatrics; Volume: 18; Issue: 12 Linguagem: Inglês

10.1542/pir.18.12.407

1529-7233

Lane M. Robson,

Urinary Bladder and Prostate Research

Diurnal enuresis (daytime wetting) is a common childhood problem that has a variety of causes, the majority of which can be determined by taking a thorough history, performing a complete physical examination, and obtaining such noninvasive tests as a urinalysis and ultrasonography of the kidney and bladder.Diurnal enuresis is an unintended leakage of urine during waking hours in an individual old enough to maintain bladder control. Primary diurnal enuresis is incontinence that persists beyond the age when a child otherwise would be expected to be toilet trained. Secondary diurnal enuresis is incontinence in a child who was toilet trained successfully and experienced at least 3 consecutive months of dry days.Daytime wetting should be considered a problem in a child older than 4 years of age who wets on most days, a child who previously was continent, or a child whose parents are concerned about the problem, regardless of the child's age.The majority of American children are toilet trained for bladder function by day at 2½ years of age. Table 1shows the percentage of children who are toilet trained by day at various preschool ages.The prevalence of daytime wetting varies by age and gender. Most children brought to the attention of a pediatrician are in kindergarten or elementary school. Approximately 3% to 4% of children between the ages of 4 and 12 years wet during the day. Table 2shows age-specific prevalence data for children who wet at least once every 2 weeks. Daytime wetting is twice as common among girls.The causes of primary diurnal enuresis include neurogenic bladder due to problems such as cerebral palsy, sacral agenesis, and myelomeningocele;congenital urethral obstruction; ectopic ureter; congenital diabetes insipidus; and any acquired cause that develops before the age that toilet training would be expected. The causes of secondary diurnal enuresis include holding the urine to the last minute, urinary tract infection (UTI),constipation, vaginal reflux of urine, labial fusion, postvoid dribble syndrome, daytime frequency syndrome, giggle incontinence, stress incontinence, emotional stress, urge syndrome, acquired neurogenic bladder,traumatic or infectious urethral obstruction, diabetes mellitus, and acquired diabetes insipidus.Holding urine until the last minute is the most common cause of intermittent wetting among preschool children, but as an isolated problem,is usually not serious enough for parents to seek the attention of a pediatrician. However, holding commonly aggravates daytime wetting that is due to other causes and might increase the risk for UTI and prolong the persistence of vesicoureteral reflux. Therefore, this behavior is important to inquire about and modify. Children who hold the urine to the last minute are usually 3 to 5 years of age. Most were toilet trained normally and experienced a period of dryness before starting to wet. Recently toilet trained children are rewarded with smiles and hugs for going to the bathroom and enjoy the attention they receive from caregivers. However, once toilet training becomes less of an accomplishment and more of an expectation, the motivation to remain dry may decrease appreciably.Children who hold their urine to the last minute are usually easy to identify. They fidget, hold themselves in the genital area, press their legs together, squirm while sitting, or otherwise adopt postures to suppress the need to void. Play environments provide endless diversions that distract a child from the signal of the need to void; they would rather "play than pee." After several signals are ignored, a detrussor contraction occurs that the child cannot suppress, resulting in an incontinent episode.Daytime wetting due to holding the urine until the last minute is less common in school-age children because wetting is a potential social problem and might result in embarrassment. Nonetheless, some elementary school-age children are reluctant to use the bathroom at school, which can lead to accidents, or the school bus might leave before the child has time to use the bathroom after classes. If the trip home is long, the child might wet on the bus or during the mad dash from the bus to the bathroom.UTI is a common cause of intermittent daytime wetting and an aggravating factor associated with other causes. Cystitis causes spontaneous detrussor contractions, which can lead to episodes of incontinence. When UTI is the only cause of daytime wetting, there usually are other symptoms of infection,and the wetting resolves with administration of an appropriate antibiotic. UTI is more common in children who have labial fusion, urge syndrome,urethral obstruction, neurogenic bladder, and ectopic ureter. In these situations, symptoms of voiding dysfunction do not resolve completely with antibiotic treatment. UTI associated with daytime wetting might present at any age, but is more common in preschool children. Older children plan activities with proximity to a bathroom in mind and are more able to suppress a spontaneous bladder contraction associated with cystitis.Constipation is a common aggravating factor. Although the mechanism is not clear, it is possible that the pressure effect of stool in the descending or sigmoid colon can trigger an uninhibited contraction of the detrussor. Constipation usually is present in children who have a neurogenic bladder and is common in those who have urge syndrome and Hinman syndrome.This problem occurs in girls who do not open the labia upon voiding, which allows some of the voided urine to "reflux" into the vagina. When the child stands to pull up her underwear, the urine leaks out and wets the underwear. This problem is common in obese girls and in preschool children who tend to "fall" through the toilet seat, which compresses the labia.Adherence of the labia minora develops following inflammation; it starts distally and can extend until only a tiny opening remains. The"pocket" behind the fused labia retains urine that is available to leak out while the child is playing. The stagnant urine is a risk factor for UTI.This commonly unrecognized problem often is misdiagnosed as vaginal reflux of urine. It typically presents in a 4- to 6-year-old girl who experiences the sensation of wetness immediately after voiding. The sensation usually lasts a few minutes, but can persist for up to 10 minutes. These girls wipe themselves repeatedly with toilet paper or change their panties several times because of the wet sensation. There is often no evidence of incontinent urine. The sensation might be due to detrussor"after-contractions."Daytime frequency syndrome occurs in preschool- and elementary-age children(mean age, 5 years), is more common among boys, and presents with the sudden onset of frequent voiding, often every 5 to 10 minutes. Although frequency is the predominant symptom, daytime wetting occurs in about 25% of these children, typically those who are younger and cannot reach the bathroom on time. Suggested etiologies include a viral or chemical cystourethritis and emotional stress.Incontinence associated with laughter is more common than appreciated and develops in up to 8% of girls. Although a source of significant embarrassment, the problem often is not brought to the attention of a pediatrician, perhaps because the episodes are infrequent. The entire bladder empties in giggle incontinence, in contrast to the smaller amount of urine associated with stress incontinence, which also can develop with hearty laughter. The problem is more common in school-age girls, is sometimes familial, and tends to improve with age.During situations associated with an increase in intra-abdominal pressure,wetting occurs if the bladder outlet and proximal urethra fail to com-pensate. Stress incontinence can develop in association with coughing, straining, or physical activity such as running, jumping, wrestling, and gymnastics.Incontinence might present as an isolated episode associated with a specific stress such as a sudden fright or as a persistent problem if the stress is prolonged. The stress associated with child abuse can manifest as daytime wetting. Excitement in preschool children, such as with trips or birthdays, is a common cause of transient urinary frequency and daytime wetting.This common cause of persistent daytime wetting is most frequent in preschool- and elementary-age girls and in children who have attention deficit hyperactivity disorder (ADHD). It presents with daytime wetting, bedwetting,urinary frequency, urgency, and squatting behavior. Up to 20% of children who have ADHD have a problem with daytime wetting. Vesicoureteral reflux is common in these children, and UTI frequently is a complicating feature. Squatting behavior, a common and distinct symptom of urge syndrome,is an attempt to suppress an unexpected and unwelcome detrussor contraction. If a child is moved or lifted during a squatting episode, a major soaking is likely. To avoid embarrassment, older children might choose not to squat,but rather pretend that something has dropped to the floor or that a shoelace is untied, and a sitting child might shift to the hard edge of the chair. The detrussor contraction can last more than 1 minute. Urodynamic studies reveal unstable detrussor contractions early in the filling phase,but this test is not necessary for a clinical diagnosis. Some children experience a period of normal voiding before the onset of the problem. The symptoms tend to improve or resolve with time and are less common after puberty.This uncommon and serious problem might represent a severe end of the urge syndrome spectrum. UTI, constipation, and encopresis are common associated problems. Diagnostic imaging studies reveal a trabeculated bladder,significant postvoid residual urine, vesicoureteral reflux, dilation of the upper urinary tract, and renal scarring.Neurogenic bladder can develop as a result of a lesion at any level in the nervous system, including the cerebral cortex, the spinal cord, or the peripheral nervous system. Up to 75% of children who have cerebral palsy experience daytime wetting. Patients who have myelomeningocele almost always have daytime wetting. Other spinal cord abnormalities, such as caudal regression syndrome, tethered cord, and tumors, can cause daytime wetting. Sacral agenesis can be associated with a neurogenic bladder and is present in 1% of infants of mothers who have type 2 diabetes mellitus. Up to 5% of patients who have imperforate anus have a neurogenic bladder;most also have a lumbosacral anomaly.Urethral obstruction can be congenital, such as with posterior urethral valves, congenital stricture, or urethral diverticuli, or acquired from a traumatic or infectious stricture. Traumatic strictures might develop after a traumatic urethral catheterization, foreign body in the urethra, or pelvic trauma. Infectious strictures are a complication of purulent urethritis due to bacteria such as Neisseria gonorrhoea. Meatal stenosis is a common cause of distal urethral obstruction in circumcised males.This rare congenital abnormality is caused by insertion of the ureter in a location other than the lateral angle of the bladder trigone. Incontinence results when the insertion is distal to the external sphincter. Ectopic ureter is three to four times more common among girls. The most frequent site of the ectopic orifice is adjacent to the external urethral meatus. Other sites include the urethra, cervix, vagina, or uterus. Boys who have an ectopic ureter are usually dry because the ureter inserts proximal to the external sphincter.Older children who have polyuria are usually dry. Wetting usually develops only in younger children who hold the urine to the last minute or in older children whose access to a washroom is restricted. Diabetes mellitus is associated with abnormalities in the afferent sensory pathways to the bladder,which might contribute to wetting.The history is the most important part of the assessment of a child who wets during the day. A meticulous history not only can establish the diagnosis, but can lead to more precise treatment recommendations and minimize the need for invasive and costly investigations.Among children who have UTI, there usually are associated symptoms of dysuria, increased frequency of voiding, urgency, and cloudy, foul-smelling urine. Children who are constipated have hard, infrequent bowel movements. Children who have vaginal reflux of urine, labial fusion, and postvoid dribble syndrome wet after voiding, in contrast to those whose enuresis is caused by other factors, who wet before they reach the bathroom. Girls who have ectopic ureters are always wet. Children who have urge syndrome present with urgency, urinary frequency, and squatting behavior. Those who have a neurogenic bladder might have symptoms related to the specific neurologic problem. Spinal cord lesions may be associated with constipation, encopresis, or a gait disturbance. Children who have urethral obstruction usually have symptoms of a urinary stream abnormality, such as the need to push to initiate or sustain voiding and a weak, interrupted, or narrow-caliber stream. It is helpful to review the symptoms and signs of a urinary stream abnormality with the parents and ask them to observe the stream at home, then report their observations at the next office visit.A thorough physical examination is important for every child who has daytime wetting. Abnormal physical findings might be found in those who have UTI, constipation, labial fusion, stress incontinence, urethral obstruction, neurogenic bladder, and ectopic ureter. UTI may be associated with fever, tenderness of the kidneys or bladder, or inflammation or discharge in the genital area. Constipation is suggested by the presence of hard stool in the left lower quadrant and hard, impacted stool on the rectal examination. The presence of wetness in previously dry underwear, after a child jumps or coughs, is a sign of stress incontinence.In patients who have urethral obstruction, the bladder and kidneys might feel enlarged upon palpation. It is important to observe the urinary stream in children in whom urethral obstruction is suspected. An audible"grunt," use of the abdominal muscles to push, or a stream that is weak, interrupted, or of narrow caliber suggests a urethral obstruction.Meatal stenosis in boys can be recognized by inspecting the caliber of the urethral meatus and the urinary stream, which is narrow and might be deflected off center.Labial fusion is evident as adherence of the labia minora. In girls who have ectopic ureter, a constant moistness is observed in the introitus, and regular drying with tissue will reveal the persistent leak of urine. The examination for neurogenic bladder should assess the motor power, tone,sensation, and spinal and plantar reflexes in the lower extremities. The anal area should be tested for an intact anal wink, and the lumbosacral spine should be examined for abnormalities, including tufts of hair, dimples,masses, or abnormal skin coloration.The urinalysis is the most important screening test in a child who wets during the day. Children who have UTI usually have white blood cells or bacteria evident in the microscopic urinalysis. Those who have labial fusion,urge syndrome, Hinman syndrome, urethral obstruction, neurogenic bladder, or ectopic ureter are predisposed to UTI. If the history or the urinalysis suggests UTI, a urine specimen should be sent for culture and sensitivity testing. Urethral obstruction might be associated with red blood cells in the urine. A random or first-morning specific gravity greater than 1.020 rules out diabetes insipidus, and the presence of glucose suggests diabetes mellitus.Uroflowmetry is a simple, noninvasive measurement of urine flow rate that is helpful in screening patients for neurogenic bladder and urethral obstruction. Children are instructed to void into a special toilet that has a pressure-sensitive rotating disc at the base. A normal uroflow study shows a single bell-shaped curve with a normal peak and average flow velocity for age and size. Patients who have urethral obstruction or neurogenic bladder have a prolonged curve or an interrupted series of curves and a low peak and average urine flow velocity. Failure to empty the bladder is a significant risk factor for UTI and is common in patients who have urge syndrome,urethral obstruction, neurogenic bladder, and Hinman syndrome. Portable bladder ultrasonography can assess residual urine in the office. The residual volume of urine normally is less than 10 mL.Ultrasonography of both the kidney and the bladder is an excellent noninvasive screening study that should be considered in all patients who have persistent daytime wetting. Patients who have urethral obstruction, neurogenic bladder, and Hinman syndrome have a thick, trabeculated bladder wall and might have evidence of hydronephrosis or cortical scarring on renal ultrasonography.If urethral obstruction is suspected based on an abnormal urinary stream or results of ultrasonography, voiding cystourethrography(VCUG) should be performed. VCUG also is appropriate if a neurogenic bladder is suspected. The lumbosacral spine should be visualized during the VCUG to look for sacral agenesis or spinal dysraphism. The classic radiologic feature of a neurogenic bladder is a trabeculated bladder with a "Christmas tree" or "pine cone" configuration. Urodynamic studies obtained during cystometrography or video-cystometrography help to clarify the diagnosis of neurogenic bladder. Patients who have evidence of a neurogenic bladder without an obvious cause should undergo magnetic resonance imaging of the spine to look for a spinal cord abnormality.One of the most important reasons to treat daytime wetting is to minimize the embarrassment of school-age children and the frustration experienced by their parents. It is important to enlist the support of the school teacher to encourage the child to go to the bathroom at recess and between activities or classes. Children should have a change of clothes at school and a plastic bag in which to store wet clothes.Children who hold the urine to the last minute should be counseled to respond promptly to the need to void. Parents should remind children to void when they wake up, about every ½ hours during the day, before leaving the house for any reason, after any significant fluid intake, and before bed. When parents note that a child is fidgeting or adopting a posture otherwise suggestive of the need to void, they should ask the child to void. The child should be advised that it does not matter whether any urine comes out; it still is important to try. There is no role for punishment. Children do not wet to create a problem. Appropriate instruction,patience, and positive reinforcement encourage resolution. Preschool children who hold the urine might respond to a reward system of praise or a sticker chart.Antibiotics are necessary if UTI is the cause of the daytime wetting, and the wetting should resolve with an appropriate antibiotic if UTI is the only cause. If the child continues to wet or has other symptoms of voiding dysfunction, another cause of wetting should be suspected. For children in whom episodes of UTI recur as frequently as every 1 or 2 months, even in the absence of a significant structural defect of the urinary tract, a 2- or 3-month course of antibiotic prophylaxis might be helpful.For children who are constipated, treatment with a high-fiber diet, mineral oil, laxative, or enema program will help evacuate the bowel and normalize bowel movements.Girls who have vaginal reflux of urine should be instructed to spread the labia with each void. Labial fusion should be treated with meticulous daily rinsing of the introital area to minimize inflammation, precise application of estrogen cream only to the fused area, and application of petroleum jelly to the separated edges to minimize the possibility of readhesion. Children who have the postvoid dribble syndrome should remain in the bathroom until the sensation has passed. Parents should teach the child to pat the genital area dry gently with soft tissue paper to minimize trauma.Parents of children who have the daytime frequency syndrome should be patient and supportive, planning activities with access to a bathroom in mind.When giggle incontinence, stress incontinence, or emotional stress is the cause of the wetting, the patient should be advised to avoid the specific circumstance whenever possible. When a situation likely to lead to wetting is anticipated but cannot be avoided, it may be helpful not to drink excessive amounts of fluid, thereby reducing the amount of urine in the bladder; to void prior to the activity; and to wear an absorbent pad in the underwear. Patients should be advised to assume a sitting position when laughing because this posture exerts pressure on the perineum, closes the urethra, and might prevent or minimize incontinence.Physiotherapy may help some patients who wet during the day because of urge syndrome, giggle incontinence, stress incontinence, or neurogenic bladder. Voluntary contraction of the pelvic floor muscles is accompanied by relaxation of the detrussor muscle. Some children require exercises to strengthen the abdominal wall and pelvic floor muscles. Others require exercises to relax the pelvic floor muscles. Pelvic floor muscle exercises consist of tightening the pelvic floor muscles and holding the contraction for 5 to 10 seconds, followed by a 5-second rest period. Children should be instructed to practice 10 contractions, several times a day, at times other than during voiding. Pelvic floor relaxation techniques require referral to an experienced physiotherapist. With voiding, the child should relax and take enough time to empty the bladder completely. Optimal posture is important. The child should sit well back on the commode and lean slightly forward with a straight back. Preschool children need a stool to support their feet.Patients who have significant symptoms of voiding dysfunction but normal results of ultrasonography of the kidneys and bladder should have more invasive investigations deferred for a 3-month period during which the voiding routine and posture are improved, constipation is treated, and UTI is treated or prevented.An anticholinergic medication might be helpful in patients who have urge syndrome, Hinman syndrome, or neurogenic bladder. These medications reduce detrussor hyperactivity, increase the threshold volume at which an uninhibited contraction occurs, and enlarge the functional capacity of the bladder. Oxybutynin chloride and hyoscyamine sulphate are commonly prescribed anticholinergic medications. Flavoxate hydrochloride, a urinary spasmolytic,is helpful in some patients who have urge syndrome, but it is only approved for children older than 12 years of age.If urethral obstruction or ectopic ureter is identified, the child should be referred to a pediatric urologist for operative repair. Neurosurgical treatment is available for spinal cord tumors and tethered cord. Management for patients who have myelomeningocele, neurogenic bladder due to central lesions, or residual neurogenic damage after surgical intervention, includes regular voiding every ½ to 2 hours, manual expression of the bladder, clean intermittent self-catheterization, and an anticholinergic medication. Urinary diversion,bladder augmentation, or an artificial urinary sphincter might be appropriate in selected cases.The prognosis for dryness is excellent for children who wet during the day except those who have neurogenic bladder and some causes of urethral obstruction. Continence is possible in up to one third of children who have myelomeningocele. Up to one fifth of patients who have urge syndrome will continue to have symptoms after puberty and into adulthood.Daytime wetting is a common problem in childhood; in most cases, it is an intermittent or self-limited problem with a benign and easily identifiable cause. The history is the most important aspect of the assessment. A urinalysis is helpful to look for UTI, and ultrasonography of both the kidney and the bladder is an excellent noninvasive screening study. More invasive diagnostic imaging studies are necessary only if the patient has symptoms or signs suggestive of urethral obstruction, neurogenic bladder,Hinman syndrome, or ectopic ureter. With time and appropriate treatment, the prognosis is excellent for the majority of patients.The authors thank Greenville Hospital System Health Sciences Library and Missy Hathcox for help in the preparation of this manuscript.