Pediatric Elimination Disorders

The main categories of pediatric elimination disorders include enuresis and encopresis. Enuresis is defined as voiding of urine into bed/clothing in children who are at least five years of age. For the diagnosis to be given, the voiding must occur at least twice per week for at least three months. Enuresis can occur during the day or at night or both. It is believed that daytime (diurnal) enuresis is different from nocturnal enuresis in biological pathways and medical comorbidity. Encopresis involves either voluntary or involuntary voiding of the bowels (fecal incontinence) in inappropriate places in children who are at least four years of age (symptoms must persist for at least three months).

Enuresis

Nocturnal enuresis usually presents with voiding of urine during sleep in a child in whom it is difficult to wake. It may be accompanied by bladder dysfunction during the day that is termed non-mono symptomatic enuresis. Daytime enuresis, also known as urinary incontinence, may also be accompanied by bladder dysfunction. Though in some cases, children may ignore a full bladder when enjoying playtime or other activities and have an accident when they can no longer hold it in.

Clinical definition of enuresis must meet the following criteria:

• The child repeatedly voids urine into bed or clothes (whether involuntary or intentional).
• The behavior must be clinically significant as manifested by either a frequency of twice a week for at least three consecutive weeks or the presence of clinically significant distress or impairment in social, academic (occupational), or other important areas of functioning.
• The child’s chronological or developmental age is at least five years of age.
• The behavior is not due exclusively to the direct physiological effect of a substance (such as a diuretic) or a general medical condition (such as diabetes, spina bifida, a seizure disorder, etc.).

All these criteria must be met in order to diagnose an individual. Generally, healthcare providers may further investigate for bladder control issues if a child is still enuretic in the daytime by age four, or if they are still enuretic at nighttime by age five or six.

Epidemiology

Approximately 10% of six- to seven-year-olds around the world experience enuresis. While 15–20% of five‐year‐old children experience nocturnal enuresis, which usually goes away as they grow older, approximately 2%-5% of young adults experience nocturnal enuresis. About 3% of teenagers and 0.5%-1% of adults experience enuresis or bedwetting, with the chance of enuresis resolving being lower if it is considered frequent.

Etiology

Figure 1. Currently, nocturnal enuresis is understood to be caused by three main underlying factors: excess urine production at night, lack of capacity for bladder storage, and inability to wake from sleep, with pathogenesis possibly varying based on the presence of daytime symptoms.

Bedwetting children are often normal emotionally and physically, although enuresis can be caused by other health conditions. Primary nocturnal enuresis can have multiple causes, which can make approaching a course of treatment more difficult. Enuresis can be caused by one or more of the following: caffeine consumption (which increases urine production), pattern and volume of fluid intake (which could be remedied by drinking more throughout the day and less in the evening before bed), less bladder capacity, dysfunctional voiding (an obstruction of the bladder due to muscles controlling urine flow that do no completely relax, thus making the person feel that their bladders is always full and strain to urinate), urinary tract infection, delay in maturation and development (which can be worsened if a child experiences stress and/or anxiety), bladder instability, nocturnal polyuria (which involves altered nighttime secretions of a hormone that controls water retention in the body), sleep disorders (specifically those that may cause an inability or difficulty arousing from sleep), and genetics (although several genes are considered of interest in relation to enuresis, lack of a single gene that may cause enuresis means that individuals of a family may have differing genetic mechanisms resulting in the condition).

One particular study examined possible environmental factors leading to enuresis and concluded that a history of anxiety in the early years of childhood (as well as a parental history of anxiety symptoms) predicted the development of this disorder; the greater the anxiety and depression, the lower the functioning at age three and more likely a child was to have a longer duration of enuresis. Children with comorbid ADHD had elevated ADHD and depression symptoms. Additionally, in line with other studies that have looked at the underlying causes of enuresis, the researchers found that humiliation and lowered self-esteem may be associated with this disorder and become a risk factor for developing symptoms of depression later on in life.^[1]

Effective Therapies for Pediatric Elimination Disorder

Urine alarm therapy involves use of sensors that detect moisture, either worn on the body or placed in a pad that lies atop the mattress. When moisture is detected, the child is alerted (e.g., alarm or tactile) to go use the bathroom. Via behavioral conditioning, the child learns to recognize when their bladder is full before the alarm sounds, thereby eliminating the need for continued use of the alarm. This approach has been extensively studied.

Dry-bed training is a multicomponent intervention. Based on operant conditioning principles, this approach pairs the urine alarm with behavioral strategies such as a frequent waking schedule and overcorrection for bedwetting (e.g., child has to change bedding). Dry-bed training is most effective when paired with the urine alarm, as opposed to use in isolation. Likewise, dry-bed training appears to be superior to the urine alarm used alone.

Full spectrum home therapy (FSHT) is a manual-based, multicomponent intervention that utilizes the urine alarm, several behavioral strategies, and graduated over-learning. Over-learning involves drinking increasing amounts of water prior to bedtime. FSHT was designed to be less burdensome on the child and family than dry-bed training (e.g., there is no frequent waking schedule).

Lifting is a Level 3 intervention. Simply, the parent lifts or walks the child to the bathroom to the toilet during the night, then returns them to bed. Despite evidence of a positive effect, there is some concern about parental burden with this treatment.

Hypnotherapy for enuresis has success rates equivalent to what is seen with spontaneous remission, without treatment (about 16%).

Retention control training involves encouraging the child to postpone urination for as long as possible. The goal is to increase bladder capacity.

Biofeedback for encopresis involves the use of electrodes or balloons, placed in or around the anus, which measure anorectal functioning. The goal is to help patients observe their own muscular contractions on a monitor and to teach them to tighten and relax anorectal muscles on command in order to improve bowel function.

Enhanced Toilet Training (ETT) is a behavior modification approach that utilizes education and training and defection (e.g., breathing techniques, training muscle contraction, and relaxation). Contingency-based reward can also be used in ETT.^[2]

Encopresis

Symptoms involve involuntary or voluntary soiling of undergarments. There are two types: with or without constipation. Those with constipation may experience a decreased appetite, abdominal pain, have pain on defecation, have fewer bowel movements, and have hard or soft stools. Those without constipation do not have these symptoms.

The DSM-r clinical diagnosis criteria are

1. repeated passage of feces into inappropriate places (e.g., underwear or floor) whether voluntary or unintentional.
2. at least one such event a month for at least three months.
3. chronological age of at least four years (or equivalent developmental level).
4. the behavior is not exclusively due to a physiological effect of a substance (e.g., laxatives) or a general medical condition, except through a mechanism involving constipation.

The DSM-5 recognizes two subtypes: with constipation and overflow incontinence and without constipation and overflow incontinence.

Epidemiology

Between 1.5% and 7.5% of children suffer from encopresis; 25% of visits to pediatric gastroenterology clinics and 3% of visits to general pediatric clinics are due to encopresis.^[3] The estimated prevalence of encopresis in four-year-olds is between 1%-3%. The disorder is thought to be more common in males than females, by a factor of six to one.

Etiology

Figure 2. The onset of encopresis is most often benign. The usual onset is associated with toilet training, demands that the child sit for long periods of time, and intense negative parental reactions to feces.

Encopresis is commonly caused by constipation, reflexive withholding of stool, due to various physiological, psychological, or neurological disorders, or from surgery (a somewhat rare occurrence). The colon normally removes excess water from feces, but if the feces or stool remains in the colon too long due to conditioned withholding or incidental constipation, so much water is removed that the stool becomes hard, and becomes painful for the child to expel in an ordinary bowel movement. A vicious cycle can develop, where the child may avoid moving his/her bowels in order to avoid the expected, painful toilet episode. This cycle can result in deeply conditioning the holding response; thus the rectal anal inhibitory response or anismus results. The rectal anal inhibitory response has been shown to occur even under anesthesia and when voluntary control is lost. The hardened stool continues to build up and stretches the colon or rectum to the point where the normal sensations associated with impending bowel movements do not occur. Eventually, softer stool leaks around the blockage and cannot be withheld by the anus, resulting in soiling. The child typically has no control over these leakage accidents, and may not be able to feel that they have occurred or are about to occur due to the loss of sensation in the rectum and the rectal anal inhibitory response. Strong emotional reactions typically result from failed and repeated attempts to control this highly aversive bodily product. These reactions, in turn, may complicate conventional treatments using stool softeners, sitting demands, and behavioral strategies.

Beginning school or preschool is another major environmental trigger with shared bathrooms. Feuding parents, siblings, moving, and divorce can also inhibit toileting behaviors and promote constipation. An initiating cause may become less relevant as chronic stimuli predominate.

Treatment

Many pediatricians will recommend the following three-pronged approach to the treatment of encopresis associated with constipation:

1. cleaning out
2. using stool softening agents
3. scheduled sitting times, typically after meals

The initial clean-out is achieved with enemas, laxatives, or both. The predominant approach today is the use of oral stool softeners like Movicol, Miralax, Lactulose, mineral oil, etc. Following that, enemas and laxatives are used daily to keep the stools soft and allow the stretched bowel to return to its normal size.

The child must be taught to use the toilet regularly to retrain his/her body. It is usually recommended that a child be required to sit on the toilet at a regular time each day and try to go for 10–15 minutes, usually soon (or immediately) after eating. Children are more likely to be able to expel a bowel movement right after eating. It is thought that creating a regular schedule of bathroom time will allow the child to achieve a proper elimination pattern. Repeated voiding success on the toilet itself helps it become a releasor stimulus for successful bowel movements.

Alternatively, when this method fails for six months or longer, a more aggressive approach may be undertaken using suppositories and enemas in a carefully programmed way to overcome the reflexive holding response and to allow the proper voiding reflex to take over. Failure to establish a normal bowel habit can result in permanent stretching of the colon. Certainly, allowing this problem to continue for years with constant assurances that the child “will grow out of it” should be avoided.

Dietary changes are an important management element. Recommended changes to the diet in the case of constipation-caused encopresis include:

1. reduction in the intake of constipating foods such as dairy, peanuts, cooked carrots, and bananas.
2. increase in high-fiber foods such as bran, whole wheat products, fruits, and vegetables.
3. higher intake of water.
4. limit drinks with caffeine, including soda and tea.
5. provide well-balanced meals and snacks, and limit fast foods/junk foods that are high in fats and sugars.

The standard behavioral treatment for functional encopresis, which has been shown to be highly effective, is a motivational system such as a contingency management system (usually an incentives-based system that rewards the child for positive behaviors and achieving goals in overcoming encopresis).