Functional Nonretentive Fecal Incontinence in Children

Abstract

Fecal incontinence, the loss of feces in the underwear after age 4 years, is a frustrating phenomenon for children and their parents. It is difficult to treat, presenting as a single symptom without any organic cause or signs of constipation. This review addresses the definition of functional nonretentive fecal incontinence and provides an overview of its epidemiology, pathophysiology, clinical features, diagnostic work-up and prognosis.

INTRODUCTION

Fecal incontinence, the voluntary or involuntary loss of feces in the underwear after age 4 years, is a frustrating phenomenon for both children and their parents. Moreover, therapeutic studies show that fecal incontinence is difficult to treat and requires patience from and a good relationship between the patients-parents and their caregivers ^(1–3). In approximately 20% of children with fecal incontinence, this entity presents as a single symptom without any organic cause or signs of constipation ⁽⁴⁾. These patients are classified as having functional nonretentive fecal incontinence (FNRFI) ⁽⁵⁾. This review addresses the definition of FNRFI and gives an overview of the epidemiology, pathophysiology, clinical features, diagnostic work-up, treatment and prognosis of FNRFI.

In 1926, Weissenberg introduced the term encopresis (from kopros, Greek for stool) to characterize the loss of stool in the underwear as the fecal equivalent of enuresis ⁽⁶⁾. Later, Bellman defined encopresis as repeated voluntary or involuntary passage of normal stools into inappropriate places (eg, clothes, floor) after the age of 4 years without any organic cause ⁽⁷⁾.

Soiling is defined as the involuntary passage of small amounts of stools, resulting in staining of the underwear. The quantity of fecal loss is the main difference between encopresis and soiling. In practice, parents are often unable to accurately estimate the amount of feces lost in the underwear and thus cannot differentiate between encopresis and soiling ⁽⁸⁾.

The term fecal incontinence encompasses both encopresis and soiling. Both terms are often associated with functional constipation ^(9–11). Levine even stated that virtually all children with fecal incontinence retain stools and are constipated ⁽¹²⁾. Recent studies reported that fecal incontinence may also occur without signs of constipation ^(3,4). Encopresis and soiling are often used indistinguishably, which creates confusion. In different cultural environments such as the United States, Europe and Australia, these terms have been used with different meanings. Physicians in some parts of the world associate encopresis with a psychological disorder and suggest that encopresis may represent impulsive action triggered by unconscious anger. Others have used the term encopresis interchangeably with fecal soiling or fecal incontinence. Furthermore, soiling has a negative undertone and is not easily accepted by parents.

In 1999 the first pediatric Rome II criteria for functional gastrointestinal disorders were formulated by a group of experts in the field of pediatric gastroenterology ⁽¹³⁾. Defecation disorders were divided into functional constipation, functional fecal retention and functional nonretentive fecal soiling (Table 1). Two studies evaluated the applicability of these criteria in clinical practice ^(14,15). Voskuijl et al. evaluated 130 patients with defecation disorders and reported that fecal incontinence was present in 79% of children diagnosed with constipation according to the Rome II criteria ⁽¹⁴⁾. Functional nonretentive fecal soiling was found in 21% of patients. Loening-Baucke found that only 3% of the 213 children with fecal incontinence fulfilled the criteria for functional nonretentive fecal soiling. Moreover, she showed that only 41% of 213 children with fecal incontinence fit the Rome II criteria of functional fecal retention ⁽¹⁵⁾, whereas 85% patients had symptoms of functional fecal retention as determined by history or physical examination, such as the passage of bowel movements obstructing the toilet and presence of an abdominal or rectal fecal mass. Clearly, the first pediatric Rome criteria were too restrictive and therefore an insufficient tool to identify and assess the severity of constipation and monitor treatment outcome. It is argued that to differentiate between retentive and nonretentive fecal soiling it is necessary to perform a rectal examination at physical examination to assess whether fecal impaction is present ^(14,15).

Table 1: Rome II and Rome III criteria

Recently, expert pediatric gastroenterologists have reached a consensus to redefine the criteria for functional gastrointestinal disorders, the so-called Rome III criteria ⁽⁵⁾. Compared to the Rome II criteria, the more neutral term fecal incontinence was adopted rather than the terms encopresis and soiling (Table 1). Pediatric fecal incontinence is divided into either organic fecal incontinence (eg, resulting from anorectal malformations or neurological damage) or functional fecal incontinence. Functional fecal incontinence can be subdivided into constipation-associated fecal incontinence and nonretentive fecal incontinence.

According to the Rome III classification, the definition used for FNRFI in this review is a history of the following criteria for at least 2 months in children of developmental age older than 4 years ⁽⁵⁾:

1. Defecation into places inappropriate to the social context at least once per month
2. No evidence of an inflammatory, anatomic, metabolic or neoplastic process that explains the subject's symptoms
3. No evidence of fecal retention

EPIDEMIOLOGY

Fecal incontinence is reported to be responsible for 3% of referrals to teaching hospitals ⁽⁴⁾. Reported prevalence of functional fecal incontinence varied between studies from 1% to 4% in children older than 4 years, 1% to 2% in 7-year-olds and 1.6% in 10- to 11-year-old children ^{(2,7,9,10,16)}. A male predominance is present, with the male:female ratio ranging from 3:1 to 6:1 ^(2,7,9). A more recently conducted prevalence study in Dutch children living in Amsterdam showed a prevalence of fecal incontinence of 4.1% in a 5- to 6-year-old age group and 1.6% in an 11- to 12-year-old age group, with a 1.5-fold higher prevalence in boys ⁽¹⁾. The drawback of all of the studies on the prevalence of fecal incontinence is that no discrimination has been made between constipation-associated fecal incontinence and nonretentive fecal incontinence.

TOILET TRAINING

Defecation is the complex interplay between muscles of the pelvic floor, the autonomic and somatic nervous system and the group of muscles controlling the anal sphincters. Many children achieve voluntary bowel control around 18 months, but the age at which complete control is attained is variable. Around age 3 years, 98% of children are toilet trained ⁽¹⁷⁾. Girls appear to become toilet trained earlier than boys because of a more rapid maturation, which is also expressed by an earlier ability to control bladder function. Development of bowel and bladder control is a maturational process, which cannot be accelerated by early onset and high intensity of toilet training ⁽¹⁸⁾. A child's initiative proves to be a reliable indicator that the child is developmentally capable of being clean and dry. Furthermore, bowel and bladder control is not affected by prematurity, adverse perinatal events or mild to moderate neurological impairment, nor is it related to psychomotor development ⁽¹⁹⁾.

CLINICAL SIGNS AND SYMPTOMS

Children with FNRFI present with fecal incontinence as single gastrointestinal symptom. In contrast to children with functional constipation, they have a normal defecation frequency and normal consistency of stools. Symptoms such as abdominal pain, difficulties with defecation or poor appetite are significantly less frequent in these children than in children with constipation ⁽⁴⁾. These children visit the outpatient clinic for the first time at an older age compared with children with constipation (eg, average age of 9.2 and 6.5 y, respectively) ^(20,21). Surprisingly, only 29% of these children had ever visited a doctor for evaluation of this problem ⁽¹⁾. The fact that these children experience no accompanying symptoms, such as infrequent defecation and abdominal pain, may be less alarming for parents, and this may result in a delay in presentation. Parents may also fail to seek help because they believe that fecal incontinence is a result of their child's laziness or they feel ashamed of their own incompetence in successfully toilet training their children ^(1,20). Furthermore, FNRFI often is not recognized as a separate clinical entity by general physicians and pediatricians, leading to a delay in referral and frequently leading to inadequate treatment, which negatively influences long-term outcome. Approximately 30% to 40% of children presenting with FNRFI have never been toilet trained successfully (primary fecal incontinence). The majority has been completely toilet trained and subsequently regressed to incontinence (secondary fecal incontinence) ^(3,20). Nighttime fecal incontinence is less frequent in children with FNRFI (12%) as compared with constipated children (30%) ⁽⁴⁾. Many children blame the occurrence of their fecal accidents on “no time to go to the toilet,” “I could not leave my computer game,” or “I sensed the urge, but I was just too late” ^(3,11). In addition, Van Ginkel et al. reported that frequency of daytime and nighttime enuresis is higher in children with FNRFI (40%–45%) compared with children with constipation (25%–29%) ⁽²²⁾. This suggests that children with FNRFI may deny or neglect their normal and appropriate physiological stimuli to go to the toilet.

PATHOGENESIS

The underlying mechanism of FNRFI is largely unknown. In the literature controversial ideas about etiology have been postulated, focusing on disturbed gastrointestinal motility and sensation, genetics, presence of psychological disturbance and psychiatric morbidity. Pathophysiology seems to be complex and FNRFI is most likely a multifactorial disorder.

Gastrointestinal Motility and Sensation

Continence depends on a variety of dynamic responses to movement of feces, such as colonic contractions, rectal compliance and accommodation, internal anal sphincter responses and rectal/pelvic sensation ^(23,24). Abnormal dynamics at 1 or more levels may be involved in the pathophysiology of fecal incontinence. These different aspects of gastrointestinal function that may play a role in the pathophysiology of FNRFI were evaluated using radioopaque markers to evaluate colonic transit time, anorectal manometry to evaluate sphincter function and, more recently, rectal barostat to assess rectal compliance and rectal sensation.

Several studies using radioopaque markers have reported that in contrast to delayed colonic transit time (CTT) exceeding 62 h found in ≈50% of constipated children, total and segmental CTT are within normal range in all children with FNRFI ^(4,25,26). These findings confirm normal daily bowel movements of children with FNRFI ⁽⁴⁾.

To study anorectal function, anorectal manometry was conducted in several studies in children with FNRFI ^(3,4,22). No significant impairment of anorectal sensorimotor function in these children was found compared with healthy volunteers. In accordance with children with functional constipation, 50% of children with FNRFI presented with abnormal defecation dynamics (eg, inability to relax the external anal sphincter during defecation) ^(3,4). Despite abnormal defecation dynamics, these children had neither prolonged rectosigmoid nor total CTT nor did the dynamics lead to abnormal defecation frequencies. This was in contrast to significantly increased total and rectosigmoid transit times found in constipated children who had abnormal defecation dynamics ⁽⁴⁾. Van der Plas et al. ⁽³⁾ showed that biofeedback training resulted in normalization of defecation dynamics in children with FNRFI. Nevertheless, this improvement of defecation dynamics was not a predictive factor for success. Moreover, no difference in success was found between FNRFI children with normalized and without normalized defecation dynamics. Based on these results, it seems that fecal incontinence in these children is not caused by an abnormal defecation technique. This pattern may be an acquired control mechanism in which after loss of the first stool in the underwear, the child contracts the external anal sphincter unconsciously to retain the rest of stools in the rectum ^(3,22).

A recent study with a pressure-controlled distention protocol applied by a rectal barostat showed that increased compliance of the rectum instead of decreased rectal sensitivity is an essential pathophysiological mechanism in children with functional constipation ⁽²⁷⁾. In those constipated children with a higher compliance, larger stool volumes are necessary to trigger urge sensation. Patients with FNFRI have normal rectal compliance, underlining the clinical and manometric findings indicating that FNRFI is a distinct clinical entity from constipation ⁽²⁷⁾.

A substantial proportion of the children with FNRFI only notices feces at the time the feces reach their underwear, sometimes shortly after an acute, irresistible urge. In some patients with FNRFI undergoing a barostat, rectal contractions accompanied by unnoticed fecal loss were observed ⁽²⁸⁾. These rectal contractions were not followed by an increase in anal sphincter pressure as adequate to prevent fecal loss. In adults with idiopathic fecal incontinence, similar observations were measured by anorectal manometry ^(29–32). Furthermore, in children with fecal incontinence caused by anorectal malformations or sacral neurological defects, there is evidence of aberrant huge amplitudes of rectal contractions, described as an “automatic” rectum ⁽³³⁾. This description resembles the symptoms of children with FNRFI. Further research is necessary to explore whether FNRFI may result from a disruption in interactions of rectal contractions and compensation reflex of the anal sphincter complex. This can be performed by using combined measurements of rectal barostat and anal manometry. A minimum age of 8 years is required to conduct such an invasive measurement because children have to cooperate.

Genetics

It is unknown whether a genetic predisposition plays a role in the etiology of FNRFI, but in ≈20% of children there is a positive family history ^(3,7,20). The question remains whether a family history originates from genetic factors or psychosocial and/or environmental influences.

Behavioral Aspects

Psychiatrists have historically viewed fecal incontinence in children as an emotional disturbance, representing an impulsive action triggered by unconscious anger ^(7,34,35). Several studies have associated fecal incontinence with different behavioral traits, such as moodiness, disobedience, attention deficits, hyperactivity, poorer social competence and learning disabilities ^(16,36–38). Cox et al. showed that children with fecal incontinence have more anxiety/depression symptoms, family environments with less expressiveness and poorer organization, greater social problems, more disruptive behavior and poorer school performance compared with children without fecal incontinence ⁽³⁹⁾. A high prevalence of behavioral symptoms may represent primary emotional problems in these children, resulting in fecal incontinence ⁽³⁶⁾.

Pediatricians have argued that behavioral problems, if present, are generally secondary to social consequences and humiliation experienced by these children because of the presence of fecal incontinence ^(40,41). Gabel et al. found mild behavioral problems in 49% of children with fecal incontinence, but behavioral scores were lower, indicating less severe behavioral problems than usually found in children referred to mental health services ⁽⁴⁰⁾. The study of Friman et al. showed similar behavioral scores in both children with and without fecal incontinence ⁽⁴¹⁾. A more recent study by Van der Plas et al. reported significantly more behavioral problems, mostly internalizing problems, in a subgroup of 35% of children with FNRFI ⁽³⁾. Successful treatment led to a significant improvement of behavioral profile in these children. These results supported the idea that occurrence and maintenance of behavioral problems in children with FNRFI are secondary to presence of fecal incontinence. Frustration and shame about the inability to control defecation and subsequent fecal incontinence seems to lead to behavioral problems in these children, but this may improve with successful treatment ⁽³⁾.

A recent population-based study investigated the prevalence of psychological problems associated with fecal incontinence in children around age 7.5 years ⁽⁴²⁾. Both children with occasional (ie, less than once per week) and frequent (ie, once per week or more) fecal incontinence showed significantly higher rates of emotional and behavioral problems compared with children without fecal incontinence. Frequent incontinence was associated with more problems compared to occasional incontinence. Parents reported higher rates of attention and activity problems, obsessions and compulsions and oppositional behaviors in children with fecal incontinence (none vs frequent fecal incontinence: 13.9% vs 38.9%, 7.5% vs 27.7%, 5.7% vs 25.4%, respectively). The children's self-reports showed higher rates of involvement in overt bullying (as both perpetrator and victim) and antisocial activities compared with children without fecal incontinence (none vs frequent fecal incontinence: 8.6% vs 18.4%, 21.5% vs 37.0%, respectively) ⁽⁴²⁾. No comparison between retentive and nonretentive fecal incontinence could be made because no clinical assessment for constipation was done, and in this cross-sectional study it remains unclear whether the psychological problems found are a cause or a consequence of fecal incontinence.

Benninga et al. found no significant relationship between behavior problem scores using the Child Behavior Checklist and rectoanal abnormalities in children with FNRFI ⁽²⁶⁾. No significant difference existed between children able or unable to relax their pelvic floor muscles during defecation attempts and their behavior profiles. Similar findings were observed in children with fecal incontinence as result of constipation ⁽⁴³⁾.

Based on the present findings, whether defecation problems result in defecation disorders or vice versa is a major question and one that is difficult to answer. In our experience only in a minority of these children is referral to a mental health professional necessary. The role of fecal incontinence therefore must be interpreted as the important factor in the occurrence and maintenance of the behavioral problems in children with defecation disorders.

INVESTIGATIONS

A thorough clinical history combined with an extensive physical examination in combination with colonic transit studies are sufficient for a diagnosis of FNRFI. In rare cases, magnetic resonance imaging (MRI) of the spine can be performed.

Clinical History

To discriminate FNRFI from constipation-associated fecal incontinence, clinical history should consist of questions concerning stool pattern: stool frequency, consistency and size of stools, occurrence of rectal blood loss, presence of painful defecation and abdominal pain. Details on fecal incontinence need to be elicited: age of onset of bowel problems, fecal incontinence frequency, time (day and/or night) and situations that may be associated with withholding behavior (eg, playing outside, watching television, using the computer). The majority of children with FNRFI have fecal incontinence in the hours after school and before bedtime, whereas nighttime fecal incontinence is strongly associated with severe constipation. A stool diary is often useful to obtain reliable information about bowel habits ⁽⁸⁾. Dietary history, appetite, urinary tract problems, growth, medication, neuromuscular development and family history of defecation disorders should be assessed. Information about psychological or behavioral problems of the child and family life events, such as birth of siblings, divorce of parents, decease of a family member and sexual abuse, is essential.

Physical Examination

Complete physical and neurological examinations should be performed in all children with defecation disorders ⁽⁴⁴⁾. Abdominal examination gives valuable information concerning accumulation of gas or feces. Perianal inspection provides information about position of the anus, perianal feces, redness, dermatitis, eczema, fissures, hemorrhoids and scars. It is important to consider the possibility of sexual abuse if upon examination anal fissures and scars are found without evidence of a medical cause for these abnormalities. These anal findings are reported to be significantly more often present in children with a history of anal sexual abuse ^(45,46). Anorectal digital examination assesses perianal sensation, anal tone, size of rectum, amount and consistency of stool in rectum, voluntary contraction and relaxation of anal sphincter and the presence of an anal wink. In children with FNRFI neither abnormality can be found on abdominal or rectal examination.

Colonic Transit Studies

Measurement of transit time of ingested radioopaque markers through the gastrointestinal tract provides crucial information about colorectal motility in children with FNRFI. CTT may be determined if after clinical history and physical examination there is still doubt whether fecal incontinence is the result of constipation. Patients ingest 1 capsule with 10 markers on 6 consecutive days, and an abdominal x-ray is obtained on day 7 to calculate CTT ⁽⁴⁷⁾. To assess bowel motility, both segmental distribution of markers as well as total CTT are calculated by multiplying the number of markers by 2.4 (eg, the number of hours in 1 day divided by the number of markers ingested daily) ⁽⁴⁷⁾. All children with FNRFI have normal segmental and total CTT, whereas ≈50% of children with constipation showed delayed CTT ^(4,25,26).

MRI of the Spinal Cord

If neurological abnormalities are present on physical examination in children with fecal incontinence, then an underlying closed spinal dysraphism, such as intradural lipoma, filar lipoma, dermal sinus or tight filum terminale, needs to be excluded ⁽⁴⁸⁾. Alarming neurological signs include motor and sensory dysfunction of the lower extremities and abnormal reflexes or abnormal anorectal sensation and anal wink ^(48,49). An MRI of the spinal cord is required in children who present with these abnormalities. In a recent study in children with intractable constipation, MRI revealed spinal cord abnormalities in 9% of patients. After surgical repair, constipation resolved in 86% of these children ⁽⁴⁹⁾. This was a retrospective study of severely constipated patients who were unresponsive to aggressive clean-out regimens; this limits interpretation of the results. No studies on the incidence of spinal cord abnormalities are conducted in children with FNRFI. A prospective study in children with FNRFI is necessary to further unravel possible underlying spinal cord abnormalities.

TREATMENT

Few randomized controlled trials have been performed in children with FNRFI. Based on these few data and our own experience, a multimodal protocol is proposed for treatment of children with FNRFI. In contrast to children with fecal incontinence and fecal retention, no laxatives should be used in the treatment of these children. After exclusion of underlying organic diseases, treatment is based on the following aspects: education, toilet training, a daily bowel diary with rewarding system and medication.

Education

In general, physicians treating children with fecal incontinence must consider that parents generally do not easily contact a doctor for advice. Advice about defecation habits is primarily given by friends and relatives. This can be explained by their unwillingness to admit their need for guidance from a physician, but it may also be the failure of the physician to open discussions about these “simple” problems.

Before treating the child with FNRFI, the physician must explain to both the child and the parents that fecal incontinence is common in childhood. Such reassurances address the isolation that parents and children may feel. The child should be encouraged, the approach should be positive and nonaccusatory at all times and it is recommended that both parents' and children's guilt be alleviated ^(50,51). It is of great importance to realize that cooperation is only possible if parents understand the physiology of the colon and defecation. Drawings illustrating the pathophysiological mechanism underlying fecal incontinence are often helpful. The parents should be instructed that the child may not always be aware of fecal accidents. The child is used to the odor of feces surrounding him and therefore does not smell this unpleasant scent. When other people intrude into this territory, they instantly smell the odor of feces. Some people find it unthinkable that the child does not feel the need to go to the toilet or bathroom to change clothes.

After this demystifying process, we emphasize to patients and parents that treatment of this clinical entity often is long-lasting and that progress is often irregular and marked by periods of improvement alternating with deterioration. Education about the different developmental stages of the child and that irregular bowel habits and other defecation problems commonly occur may improve parental confidence and their competence in guiding the child to normal bowel habits. Finally, parents must be informed that severe complications are rare.

Toilet Training and Daily Bowel Diary With Reward System

A strict toilet training program is the cornerstone of the treatment of children with FNRFI. The training consists of trying to defecate for 5 min after each meal and immediately after school because this is the time of day that most of these children experience fecal incontinence. The purpose of this strategy is to teach children to take time to defecate. A kitchen timer can be useful. Small children may need a foot support to sit comfortably and straighten the anorectal angle during defecation. Children must play an active role while sitting on the toilet.

The physician should explain and demonstrate to the child how to relax the legs and feet, how to take in a deep breath and hold it while sitting up straight, and how to push down with the held breath and pull in from the lower abdomen (rectus abdominis muscle) to propel a stool. Some researchers advocate “hand feedback” by placing 1 hand on the abdomen just below the navel to feel the abdomen move out when the breath is pushed down, and placing the second hand just below the first to feel inward movement with contraction of the rectus abdominis. Parents are instructed to prompt these behaviors at home. In our clinic we suggest that children inflate a balloon to mimic defecation during at-home toilet training ⁽⁵²⁾. During toilet training children should focus only on their defecation without any distractions (eg, playing with computer games or reading books is not allowed). Again, a nonaccusatory, gentle approach is needed, and therefore a reward system is useful. Problems during toilet training may occur when parents ignore the child's signs of readiness or if the training is postponed because of conflicts between parents and child.

In addition, the child and parents should keep a daily bowel diary to gain better insight into the frequency and time of fecal incontinence. The diary illustrates improvement during treatment. The goal is to teach children that regular toilet use is needed and that they should go to the toilet immediately when they feel the urge to defecate ^(50,51).

Biofeedback Training and Medication

Biofeedback training involves instilling a habit based on reinforcement and is derived from a psychological learning theory. Anorectal monitoring instruments are used to amplify selected physiological processes to make previously unavailable physiological information available to the subjects' consciousness. Feedback about the voluntary controlled muscles such as the external anal sphincter, the muscularis puborectalis and pelvic floor can be provided with verbal, visual or auditory signs. Computers convert the sign into a visual display to show contractions or relaxations of the rectum and the sphincter complex. After showing normal tracings of defecation, the child is asked to bear down and expel the balloon filled with 20 mL of air by increasing abdominal pressure and relaxing the sphincter complex. An additional rectal balloon is required for the evaluation and training of rectal sensation. Training sensation is done by inflating the balloon at different times and at different volumes and asking the child to provide a response whenever sensation is perceived. The trainer impresses upon the children that they should go immediately to their at-home toilet the moment they feel the same sensation that they learned during biofeedback training.

Van der Plas et al. performed a controlled randomized trial comparing conventional therapy (dietary and toilet advice in combination with oral and sometimes rectal laxatives) (n = 32) with conventional therapy along with 5 biofeedback sessions (n = 39) ⁽³⁾. A total of 71 otherwise healthy children with FNRFI were included in the study. All of the patients had long-standing FNRFI and were referred to a tertiary pediatric gastrointestinal center. Main outcome measures were successful treatment and psychosocial function after treatment was assessed with the Child Behavior Checklist. Success was defined as <1 episode of fecal incontinence for 2 weeks. At the end of the 6-week intervention period, children in the biofeedback group had higher success rates than those who received laxatives alone (39% vs 19%). However, at the end of 12 and 18 months, ≈50% of children in each group was successfully treated. No additional effect of biofeedback training on behavior scores was found. Based on the results of this study, fecal incontinence in children with FNRFI seems not to be caused by abnormal defecation technique.

The clinical history, as described by parents of patients with FNRFI, suggests that these children use their underwear as a toilet. The role of laxative treatment in children with FNRFI is thus questioned. Van Ginkel et al. evaluated this hypothesis in a prospective randomized, nonblinded clinical trial comparing oral laxatives (lactulose) and biofeedback training (n = 23) versus biofeedback training alone (n = 25) ⁽²²⁾. Successful treatment was defined as <1 episode of fecal incontinence for 2 weeks. At the end of the 7-week intervention period, the number of fecal incontinence episodes was significantly decreased in both groups: from median 7 (range, 2–24) to 2 (range, 0–17) in the biofeedback group and from median 7 (range, 3–25) to 2 (range, 0–14) in the biofeedback with laxatives group. However, children receiving biofeedback alone had significantly higher success rates than children receiving biofeedback with oral laxatives (44%–11%). The authors showed no additional effect of biofeedback with laxatives treatment on the decrease of fecal incontinence in children with FNRFI. Moreover, a significant negative effect on successful outcome was found in children treated with laxatives. This study shows that indeed laxatives soften stool and have a positive effect on gastrointestinal motility, but they subsequently lead to an increase of urge to defecate, which finally results in an increase in the number of fecal incontinence episodes.

In the mid-1990s we hypothesized that children with FNRFI deny or neglect their normal and appropriate physiological stimuli to defecate in the toilet. We recently observed the occurrence of rectal contractions accompanied by unnoticed fecal loss during barostat studies in some of these patients. These rectal contractions were not followed by an increase in adequate anal sphincter pressure to prevent fecal loss. Loperamide, an opioid receptor agonist has been shown to increase anal sphincter pressure, possibly contributing to better sphincter function ⁽²⁸⁾. It is a well-established compound in the treatment of diarrhea accompanied by fecal incontinence and idiopathic fecal incontinence in adults. Moreover, a clinical benefit of loperamide is reported in children with fecal incontinence resulting from neurological disorders or surgical procedures. A recent published case report in this journal described a father and son with childhood-onset, long-standing FNRFI ⁽²⁸⁾. To avoid systemic side effects (dizziness, headache, abdominal discomfort, nausea, and vomiting) 10-mg loperamide suppositories were administered twice daily. After 3 d, the son experienced constipation, and the dose was lowered to 5-mg loperamide twice daily. During the next 3 weeks, defecation frequency normalized without any episodes of fecal incontinence. Both the father and the son reported no side effects. Surprisingly, discontinuation of the medication immediately resulted in a relapse of fecal incontinence in both patients. The beneficial effect of loperamide was not the result of its antidiarrheal effect, but most likely that loperamide reduced the number of fecal incontinence episodes by increasing the basal internal anal sphincter pressure, by decreasing rectal contractions, or both. Prospective controlled trials are needed to evaluate the potential benefits of loperamide application and to investigate other therapeutic options to improve the treatment of children with FNRFI.

Behavioral Intervention

The aim of behavior treatment (toilet training in combination with reward system, diminishing toilet phobia) in combination with cognitive therapy (psychotherapy, cognitive therapy and family therapy or educational support) aims to lower distress and develop or restore normal bowel habits by positive reinforcement, preservation of self-respect and encouragement of both child and parents during treatment. Well-designed studies to determine precisely the role of behavioral treatment in combination with cognitive therapy in children with FNRFI are urgently needed. In 2006 Brazzelli et al. performed a systematic review to evaluate behavioral and cognitive interventions with or without other treatments for the management of fecal incontinence in children ⁽⁵³⁾. This review included 18 randomized trials with a total of 1168 children. Sixteen trials enrolled children with functional fecal incontinence and 2 trials enrolled children with fecal incontinence due to congenital abnormalities. Among the 16 trials assessing children with functional fecal incontinence, 11 studied children with a history of constipation and/or fecal impaction, 4 studied primary and secondary fecal incontinence, and 1 trial studied fecal incontinence with or without constipation. The drawback of this systemic review was that no clear distinction was made between FNRFI and constipation-associated fecal incontinence. The authors concluded that there is some evidence that behavioral interventions plus laxative therapy, rather than laxative therapy alone, improves continence in children with constipation-associated functional fecal incontinence. No conclusions were made about children with FNRFI.

FOLLOW-UP AND PROGNOSIS

To our knowledge only 1 study describes long-term follow-up in children with FNRFI. Voskuijl et al. ⁽²⁰⁾ studied 114 children with FNRFI for approximately 10 y after they had participated in 2 randomized trials performed in a tertiary pediatric gastrointestinal center ^(3,22). After the study program all of the patients were contacted at 6, 12 and 18 months and annually thereafter. A standard interview was used in all patients during an outpatient visit or by telephone when the child had been discharged. Clinical success was defined as having <1 episode of fecal incontinence for 2 weeks while not using medication, such as loperamide, for at least 1 month ⁽²⁰⁾.

After 2 years of intensive medical and behavioral treatment, only 29% of children were treated successfully. This result is in contrast to earlier findings in a long-term follow-up study in 403 children with chronic constipation, which reported that 52% of these children were treated successfully after 2 years, with ≈10% of children still using laxatives ⁽⁵⁴⁾. After 5 years of follow-up almost similar success rates were observed in children with constipation and patients with FNRFI—70% and 65%, respectively. Thereafter, success was further increased to 90% in patients with FNRFI, whereas the percentage remained stable (≈70%) in children with constipation ^(20,54).

Successful treatment according to biological age showed that at age 12 years 49% of patients with FNRFI were still unsuccessfully treated. From that age on, a steady increase in success rates was observed, and at 18 years of age, 85% of patients were symptom-free ⁽²⁰⁾. In children 12 to 18 years old with constipation, less increase of success percentages (62%–72%) was seen ⁽⁵⁴⁾. The fact that FNRFI persisted in 15% of children is in contrast to the assumption that fecal incontinence is unusual after age 16 years ⁽⁵⁵⁾. No prognostic factors for success were found. This follow-up study is limited by bias in the study population. Only patients with such severe symptoms that referral to a tertiary medical center was necessary were included. Follow-up studies in primary health centers are needed to provide further information on the prognosis of FNRFI.

SUMMARY

Fecal incontinence is a common symptom in children with functional defecation disorders. However, FNRFI as a separate clinical disorder is often not recognized by medical healthcare workers. This often causes a delay in referral and frequently leads to inadequate treatment, which negatively influences long-term outcome. Children with FNRFI have, in contrast to children with constipation, normal bowel movements and no abdominal or rectal fecal impaction. Therefore laxatives are contraindicated in these children. Although 40% of these children have behavior scores within the clinical range, children with FNRFI can be characterized as having only mild psychiatric problems, suggesting that these children should be treated primarily in a pediatric setting and not in a psychiatric outpatient clinic. Treatment consists of education and toilet training combined with daily bowel diary and reward system. Follow-up of these children is important because treatment is often long-term, relapses are frequent and symptoms persist in 15% of children into young adulthood.

Future research focusing on a better understanding of pathophysiological mechanisms is necessary to develop more targeted therapeutic interventions. Double-blind randomized controlled trials need to be performed to determine efficacy and safety of new treatment options such as loperamide in children with FNRFI. Epidemiology and long-term treatment outcome of FNRFI should be assessed by cohort studies in both primary care centers and specialized centers for pediatric gastroenterology. The development of Rome III criteria defining pediatric functional gastrointestinal disorders, including FNRFI, may lead to more international collaboration in future research and better understanding of this disorder.