Encopresis in childhood

1.    Definition and Introduction

Image courtesy of FirstCry Opens in new window Encopresis is defined as persistent fecal incontinence Opens in new window without associated anatomic abnormality. Encopresis is incontinence of stool not resulting from organic defects or illness, in other words. The term encopresis was introduced in 1926 by Weissenberg to describe the fecal equivalent of enuresis Opens in new window.

Encopresis is considered to be a primary disorder associated with chronic constipation Opens in new window, with stool retention in 96% of children over the age of four years presenting with fecal incontinence. This fecal incontinence characteristically ceases for several days following expulsion of a megastool.

Encopresis rarely occurs before 3 years of age. In 102 encopretic patients seen at Boston Children’s Hospital Medical Center over an 18-month period in the early 1970s, the mean age was 7 years, 4 months. At the James Whitcomb Riley Hospital for Children/Indiana University Medical Centre in Indianapolis, 274 children with constipation were seen in the gastroenterology clinic in 1992. Seventy-five of these children had fecal soiling. The median age of these encopretic patients was 9 years.

Encopresis is a source of considerable embarrassment for the child, who must deal with taunting by peers. These patients may suffer significant emotional setbacks as a result of this problem, with loss of self-esteem and confidence.

Encopresis also is the source of a good deal of frustration for the parents who must deal with the smelly, dirty laundry and often angry school officials. These parents are convinced that their child has an anatomic abnormality of the colon by the time they arrive at the office of the pediatric gastroenterologist.

Often punishment and psychotherapy have been tried, without beneficial results. Many parents are visibly relieved when the pathophysiology of the condition is explained to them. A few demonstrate initial skepticism, finding it difficult to accept the simple explanation for a problem that they have become convinced has an organic basis.

Although encopresis is considered by some to be caused by emotional upheavals, rarely is a nonconstipated child with severe psychological disturbances seen who passes stool in clothing.

Furthermore, psychotherapy has been unsuccessful as a sole treatment for encopresis. It is now generally accepted that chronic constipation resulting from functional fecal retention, often called psychogenic constipation, is the major cause of encopresis. Fecal incontinence owing to organic disorders, including spinal cord lesions or anatomic lesions of the anorectum, is not encopresis.

Encopresis often resolves spontaneously before late adolescence, but Rex and colleagues have reported four patients with encopresis whose ages ranged from 16 years to 20 years, showing that this condition may persist into young adulthood.

2.    Epidemiology and Natural History

Boys are far more likely to experience encopresis than girls, with the prevalence of encopresis amongst 7 to 8 year old boys 2.3 percent and amongst girls of 0.7 percent in the classic study from Stockholm.

The Isle of Wight survey found that 1.3 percent of 11 year old boys and 0.3 percent of girls were incontinent of stool. In the Boston study, the male-to-female ratio was 5.8:1; in the Indianapolis study, it was 2:1.

Approximately 70 to 80 % of children presenting with encopresis are boys. The proportion of boys in studies of children with chronic constipation is approximately 60 percent.

In adults the picture is reversed with women being more inclined to suffer from constipation Opens in new window and incontinence Opens in new window. However, in the clinical group of 276 patients described by Speakman and Henry, if men and women who had previous surgery or trauma and the women who had a history of difficult vaginal delivery were discounted then the remaining patients consisted of 6 women and 4 men. Obviously when comparing childhood and adult prevalence of any disorder it is necessary to discount adult conditions for which there is no pediatric equivalent.

Fecal incontinence Opens in new window tends to be underreported in medical histories, like leading to systematic underestimation of its incidence and prevalence in adults. In one study, only 5% of patients with self-reported fecal incontinence had this recorded in their medical history. Of the 46% controls who responded to the questionnaire, 5% indicated they experienced fecal soiling. It was suggested that either the doctor might be reluctant to treat the problem, or alternatively that they regarded it as a minor symptom.

Therefore assessment of the recovery rate of children with encopresis by comparison of reported prevalences is open to gross inaccuracies. It seems likely that the same bias occurs in pediatric reporting.

In their study of 176 consecutively referred children with constipation, Arhan et al. reported a referral diagnosis of encopresis in 8% but in fact 68% of the 176 children suffered from this symptom.

There are functional differences in continence mechanisms between normal adult men and women. These include greater activity of both sphincters in men and a lower rectal volume to reach the threshold for desire to defecate in women. There are dangers inherent in extrapolation from the physiology of adults to children but it has suggested that gender differences also exist in pediatric anorectal function which might explain the greater proportion of boys with anorectal dysfunction.

To date most studies which have included a comparison group of control children have not found evidence to support this suggestion. Corazziari did study 78 healthy children as a comparison group for 63 chronically constipated children and found no gender difference in stool frequency or total gastrointestinal transit time. Only 25 (13 boys) children had manometric studies and there were no gender differences identified. Similarly, Meunier et al. found no significant gender differences in two control groups of normal children (n=32 and 31).

3.    Treatment

The aim of treatment is for the patient to achieve the ability to be in charge of his/her own continence and defecation. To this end the any significant fecal impaction needs to be relieved and a regular output established.

Treatment for encopresis falls into three stages with the first being initial disimpaction with commencement of maintenance laxatives or prokinetic agents. The second stage is the establishment of a good bowel habit by the use of behavior modification; and thirdly, the correction, if necessary, of abnormal defecation dynamics.

The first two models of treatment are frequently adequate to resolve the problem but if the encopresis is refractory. Many children respond well but there is undoubtedly a group who continue to have long term problems past puberty.

3.1.     Laxatives

Laxatives treatment regiments vary in detail but generally aim to produce one to two bowel movements per day. The extent of the fecal retention determines the type of medication. Polyethylene glycol (“macrogol”) based regimens are increasingly accepted as a first line, but there is still an occasional place for stimulant laxatives such as senna derivatives or bisacodyl. Enemas and suppositories are now only infrequently used for disimpaction. Increased fibre is of use only if the current intake is inadequate.

3.2.     Behavior modification

Concurrently with laxative medication, a star chart with a reward system both for successful defecation in the toilet and for soil-free days can be used as positive reinforcement aimed towards achieving an improvement in toileting habit. Regular sits three times a day for 5–10 minutes with a minimum of distraction is an effective regimen.

In addition, clarification of the physiology of encopresis to parents and children to alleviate guilt is very important, as is attentive follow-up to maintain compliance and monitor progress. In a referred population of children presenting with encopresis this regimen can be expected to result in complete remission from soiling in approximately half, and in addition to be independent of laxatives in the same or less.

3.3.     Biofeedback for Treatment of Anismus

The rationale for the development of biofeedback had been to provide a correction of disturbed anorectal dynamics, and especially for paradoxical sphincteric contraction or anismus. The method recommended for biofeedback generally is the same as, or an adaption of, anorectal manometry with some sort of visual or auditory feedback of sphincteric contraction. Unfortunately critical evaluation in controlled studies has failed to provide evidence of superior efficacy to standard treatments.

4.    Discussion

Encopresis in childhood is an important cause of soiling, with socially disabling consequences. It is usually associated with constipation and is thought to be secondary to periodic relaxation of the anal sphincters in the presence of a loaded rectum with secondary seepage.

The pathophysiology of disturbed anorectal function is relatively poorly studied in children and results often interpreted with data obtained from adult studies. Most children do have some type of manometric abnormality and may have a degree of rectal enlargement. Dynamic abnormalities also exist and the best studied is paradoxical sphincteric contraction or “anismus”.

Treatment regimens which include a combination laxatives for disimpaction and maintenance, together with behavioral interventions centered around encouraging toileting are generally effective but there is a group of children who go on to have significant long term problems.