Encopresis & MIE (DoD #2)

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 150 children, ages 5 to 12 years, 11 months
with ASD and encopresis. Subjects will be randomized in a 2:2:1 ratio to receive either one
week of MIE, two weeks of MIE or one week of TAU.

Inclusion Criteria:

- Males and females > 5 years of age and ≤ 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.

- Less than 60% of days are continent days or more than 1 day out of 7 is an incontinent
day over the past two weeks (Continent day is defined as a day with at least one
continent bowel movement and no incontinence. 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 - one or fewer episodes of incontinent urination each day

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.