Treatment of Encopresis in Children With Autism Spectrum Disorders

This study is comparing a multidisciplinary intervention for encopresis (MIE), consisting of both medical and behavioral components to treatment as usual control (TAU). Participants are first screened by a pediatric gastroenterologist and assessed and treated for any constipation or other potential medical complications. Following this, caregivers collect data on bowel movements and continence during a home baseline lasting no less than 14 days and no more than 21 days. Participants randomly assigned to treatment as usual or the treatment group, and begin attending daily appointments in clinic for 2 weeks. At appointments, the behavior team implements structured sits on the toilet to promote independent bowel movements (BMs). If an independent BM does not occur, the study team will administer a suppository to promote rapid release of the bowels and prompt the child to remain on the toilet following administration. In doing so, continent bowel movements are predictably evoked while the child is on the toilet, allowing for reinforcement with praise and preferred toys/activities. Eventually, suppositories are gradually decreased until the child is having BMs independently. Caregivers are trained to continue implementing the intervention following the clinic-based portion.

The purpose of the current study is to evaluate MIE using a large randomized clinical trial (RCT), addressing the Department of Defense Autism Research Program, Area of Interest of Therapies to Alleviate Conditions Co-Occurring with autism spectrum disorder (ASD). The researchers will recruit 112 children diagnosed with ASD, randomizing them to two weeks of MIE, or treatment as usual (TAU) consisting of behavioral consultation and medical intervention. This study will evaluate MIE compared to TAU and determine the optimal treatment length.

Toilet training one's child is a nearly universal challenge for parents, but is a particularly distressing ordeal for parents of individuals with autism spectrum disorder (ASD). Whereas typically developing children generally stop having daytime toileting accidents (i.e., they achieve continence) by 2-4 years of age, most individuals with ASD are either delayed in their acquisition of toileting skills, or never achieve continence. Furthermore, toileting concerns are a significant contributor to the increased stress experienced by caregivers of those with ASD. Besides dramatically increasing their burden of care, not being fully toilet trained negatively impacts the individual with ASD's hygiene, self-confidence, physical comfort, and independence while also causing social stigma. Incontinence can also have serious collateral consequences, such as limiting exposure to important life experiences. Furthermore, without effective treatment these problems generally persist into adulthood.

One reason why strictly behavioral treatments of encopresis have shown only limited success may be due to the fact that it often has a medical etiology. Encopresis is when underwear are soiled by stool in children over the age of toilet training and long-standing constipation is the cause of encopresis in the majority of children who exhibit it. Children with ASD are more likely to have constipation than typically developing children. Constipation causes encopresis by creating a cycle of withholding bowel movements (withholding is the voluntary contraction of the external sphincter to avoid a bowel movement): constipation causes painful bowel movements, which triggers further withholding behavior, exacerbating constipation. Over time the colon adapts by dilating, which leads to larger fecal masses in the rectum. Thus, the passage of larger and harder (i.e., painful) stools further increases an individual's withholding behavior. Over time, the rectum and colon become so dilated that the individual loses sensation. With no urge to defecate, an individual is even more likely to have stool accumulate in the rectum and is also unable to control bowel movements. Looser stool may leak around hard stool leading to an unintended leakage and sometimes large evacuation of stool occurs without the individual realizing it.

Although purely medical approaches can successfully treat constipation in individuals with ASD, they have not shown long term success with encopresis. That is, medical approaches can treat a single episode of constipation, but without acquiring toileting skills, the individual is likely to become constipated again, repeating the cycle. Conversely, purely behavioral strategies have not been shown to be effective at treating encopresis in individuals with ASD, even when they are not experiencing constipation. One reason for this lack of success may have to do with the fact that it is often difficult to predict the timing of a bowel movement so that caregivers can ensure the individual is sitting on the toilet when one takes place and then reinforce continence. Thus, a multidisciplinary approach incorporating both medical and behavioral approaches is necessary in the treatment of encopresis in individuals with ASD.

This is an 8-week, randomized clinical trial of 112 children, ages 5 to 12 years, 11 months with ASD and encopresis. Participants will be randomized to receive either two weeks of MIE or one week of TAU. The study initially had a third study arm of one week of MIE treatment, which was discontinued in October of 2019.

Eligibility Criteria:
Inclusion Criteria:

* Males and females from 5 years of age to 12 years 11 months of age.
* Diagnostic and Statistical Manual of Mental Disorders (DSM-5) diagnosis of Autism Spectrum Disorder as established by clinical assessment, corroborated by the Autism Diagnostic Observational Schedule, Autism Diagnostic Interview-Revised and/or Childhood Autism Rating Scale-Second Edition.
* Fewer than 60% of days are continent days or more than 1 day out of 7 is an incontinent day over the previous 7 days (a continent day is defined as a day with at least one continent bowel movement. An incontinent day is a day with an incontinent bowel movement regardless of whether a continent bowel movement also occurs).
* Medication free or on stable medication (no changes in past 6 weeks and no planned changes for the next 6 months).
* Urine continent - Over half of the voids are continent when the child is with the parent and when the child is on a typical toileting routine.

Exclusion Criteria:

* Presence of a known medical condition in the child (based on medical history or physical examination) that would interfere with child's ability to control his/her anus. These include: history of any anal surgery, spinal dysraphism (e.g., spina bifida), other neurologic disorder affecting anal function, and prolonged/recurrent gastrointestinal infectious disease (e.g. Clostridium difficile colitis). In addition, the following may constitute exclusions following evaluation by a physician: inflammatory bowel disease, short gut syndrome, chronic diarrhea, or history of intestinal/abdominal surgery.
* Presence of a current serious behavioral problem or psychiatric condition that would require another treatment (e.g., psychotic disorder, major depression, moderate or greater aggression, severe disruptive behavior), based on information collected at screening and the Behavior Problems Inventory-01 (BPI-01).
* Currently receiving and caregiver refusal to discontinue ongoing behavioral or alternative medical intervention for encopresis.