Loperamide Suppositories in an Adolescent with Childhood-Onset Functional Non–Retentive Fecal Soiling

Encopresis is characterized by the voluntary or involuntary passage of stool into the underwear after the age of 4 years. In most patients, encopresis is the result of constipation. However, in our practice, 20% of children experience encopresis as an isolated complaint, without any signs of constipation. These children have normal defecation frequency, no palpable abdominal or rectal fecal mass on physical examination, and normal colonic transit time. Laxatives have no or an adverse effect in these children (¹).

Recently, encopresis in the absence of signs of fecal retention has been classified as functional non-retentive fecal soiling by the new pediatric Rome-II criteria (²).

The treatment of these children is often disappointing, with only 29% of patients cured after 2 years of intensive treatment (³). In contrast to earlier reports (⁴), recent data show that 24% of children with functional non-retentive fecal soiling do not outgrow their encopresis during puberty and still experience encopresis when reaching adulthood (⁵). This large number of patients with encopresis after the age of 18 justifies the search for treatment options for this patient group.

The symptoms of children with functional non-retentive fecal soiling resembles those of adults with idiopathic fecal incontinence, incontinence without a known underlying cause. In most adult patients, however, fecal incontinence is a result of trauma (after delivery) or by the aging processes. In adulthood fecal incontinence, loperamide is a well-known and frequently used medication. A study in adults with chronic diarrhea and fecal incontinence showed that the oral administration of loperamide, an opioid agonist, resulted in significant improvement of continence (⁶).

Here, we describe a 20-year-old male with childhood-onset, longstanding functional non-retentive fecal soiling who dramatically improved after rectal application of loperamide.

CASE REPORT

A 20-year-old male with primary encopresis had been treated at our outpatient clinic since the age of 13 years. He passed meconium within 24 hours of birth and never experienced any defecation problems during his toddler years. However, at the age of 9, despite a normal defecation frequency, he was still not fully toilet trained. He had no other gastrointestinal symptoms and he had a normal appetite. He had received treatment with various laxatives, prokinetics, and mineral oil without any improvement in his incontinence.

He was referred to our motility unit to exclude Hirschsprung disease. At that time, encopresis was occurring daily. Most “accidents” occurred during physical exercise and stressful moments (birthday, school exams). He had a normal urge to defecate, but experienced urgency resulting in fecal incontinence. Stool consistency was always normal. He also reported nocturnal enuresis twice weekly, whereas daytime enuresis did not occur. Abdominal and rectal examination revealed no fecal retention. Except for his father, who had experienced idiopathic fecal incontinence, his family history was negative for significant gastrointestinal disorders. His IQ was 89 and he received some special education classes. Psychologic examination was normal. Anorectal manometry at the age of 12 showed a normal resting and squeeze pressure, normal expulsion profiles, and a normal threshold for first sensation (25 mL). A normal anorectal inhibition reflex excluded Hirschsprung disease. Total colonic transit time measurement, using the Metcalf method (⁷), was 33.6 hours, well below the upper limit of normal transit (62 hours) (⁸).

Discontinuation of the longstanding, intensive laxative treatment did not alter his defecation pattern. Subsequently, at the age of 14, five sessions of biofeedback training were given without clinical improvement. Thereafter, a strict toilet training program (three times daily for 5 minutes) was recommended without the use of any medication. The patient visited our outpatient clinic every 6 months for follow-up. The symptoms of encopresis never resolved during the 6 years of follow-up.

Based on adult literature showing beneficial effects of loperamide on fecal continence, a trial of loperamide was started at the age of 20 years. Written informed consent was obtained. Before the actual treatment, a 1-month bowel diary showed a defecation frequency of 20 times per week (on the toilet) with daily encopresis (in his underwear).

To avoid systemic side effects (dizziness, headache, abdominal discomfort, nausea, and vomiting) we administered loperamide-suppositories 10 mg twice daily (⁶). After 3 days, he experienced constipation, and consequently the dose was lowered to 5 mg loperamide twice daily. During the next 3 weeks, his defecation frequency was 14 times weekly without any episodes of encopresis. Stool consistency was normal. No side effects were reported. Discontinuation of the medication immediately resulted in a relapse of encopresis.

Currently, 18 months after initiation of therapy, our patient uses loperamide 5 mg daily and remains continent without any side effects.

DISCUSSION

Encopresis in children older than 4 years of age is a frequent reason to consult the pediatrician. Despite the high prevalence of encopresis, 1% to 2% in otherwise healthy school children, a first visit to the pediatrician is frequently delayed because of shame and cultural taboos (⁹). This was the case in our patient.

In our motility unit, 80% of children with encopresis fulfill the criteria for childhood constipation. In the remaining 20% of patients with encopresis, no criteria for constipation can be identified. These children have been classified as having functional non-retentive fecal soiling by a group of experts (²).

Earlier opinions state that encopresis will resolve spontaneously during adolescence; however, in our experience, encopresis can persist even after primary school. Furthermore, there are no data in the published medical literature to support the statement that functional non-retentive fecal soiling resolves spontaneously during puberty. Long-term follow-up of functional non-retentive fecal soiling patients shows that approximately one in four patients remains encopretic when reaching adulthood (⁵). This considerable percentage underscores the importance of some form of effective therapy for this patient group.

Recently, we observed the occurrence of rectal contractions accompanied by unnoted fecal loss during barostat studies in some of these patients (data submitted for publication). These rectal contractions were not followed by an increase in anal sphincter pressure adequate to prevent fecal loss. These observations are similar to those from manometric studies in idiopathic fecal incontinence and chronic diarrhea accompanied by fecal incontinence in adults (¹⁰).

Loperamide, an opioid-receptor agonist that inhibits peristaltic movement by reducing the release of acetylcholine and prostaglandin during distension in vitro (¹¹), is a well-known therapy for fecal incontinence in adulthood. Furthermore, it is a well-established agent in the treatment of diarrhea accompanied by fecal incontinence and idiopathic fecal incontinence in adults. Loperamide has been shown to increase anal sphincter pressure, possibly contributing to better sphincter function (⁶). Moreover, a clinical benefit of loperamide is reported in children with fecal incontinence resulting from neurologic disorders or surgical procedures (¹²).

Because all therapy so far had been unsuccessful, we evaluated the effect of rectal loperamide in our adult patient with longstanding, childhood-onset functional non-retentive fecal soiling. Immediately after initiation of loperamide 10 mg, our patient experienced constipation. Decrease of the dose to 5 mg twice daily resulted in a complete disappearance of the encopresis episodes with daily defecation and no side effects. During follow-up, he experienced a relapse of symptoms when discontinuing medication.

It is important to stress that the pathophysiologic characteristics of fecal incontinence in adulthood are different from those of childhood functional non-retentive fecal soiling. Our patient was an adult when we first administered loperamide; nevertheless, he was experiencing symptoms of a disease he had acquired in childhood.

Until now, loperamide has not been prescribed for encopresis in childhood because the cause of encopresis has been assumed to be constipation. Only recently was it suggested that encopresis in the absence of signs of constipation is a distinct entity. In adult fecal incontinence, which has different pathophysiologic features, loperamide has been used successfully for many years. It is therefore very interesting that a well-known medication for a symptom in adulthood resulted in such a substantial effect in this patient with a childhood-onset disease in adulthood.

To our knowledge, this is the first report of the use of loperamide in the treatment of longstanding, childhood-onset functional non-retentive fecal soiling. Because we did not assess anorectal motility, we can only speculate on the mechanism of action of loperamide in our patient. Because he had a normal defecation frequency (on the toilet) and a normal stool consistency, the beneficial effect of loperamide was not the result of its anti-diarrheal effect. It is most likely that rectal application of loperamide reduced encopresis by increasing the basal internal anal sphincter pressure, by decreasing rectal contractions, or both.

Because we believe that loperamide may have a beneficial role in childhood-onset functional non-retentive fecal soiling, we have recently initiated a large, prospective placebo-controlled trial to evaluate further the potential benefit of rectal application of loperamide in this condition.