Comprehensive Toileting Programming: Enuresis Treatment to a Randomized Clinical Trial of a Caregiver-Mediated Multidisciplinary Intervention for Encopresis - Project Summary/Abstract Encopresis (fecal incontinence) and enuresis (urine incontinence) are prevalent in autistic youth and can have a negative impact on quality of life (Kroeger et al., 2009). Evidence supports behavioral interventions for enuresis. However, encopresis persists despite successful intervention for enuresis for a subset of autistic youth (Lomas Mevers et al., 2018). Unfortunately, the timeline for achieving fecal continence after successfully completing enuresis treatment is unclear and there is no available evidence on which individuals are likely to acquire fecal continence independently after urine treatment versus those who will continue to experience encopresis and require additional intervention. For those individuals who do require specific intervention for encopresis, our group has developed and tested the Multidisciplinary Intervention for Encopresis (MIE), which integrates physiological mechanisms (resolution of constipation before treatment and use of suppositories in treatment, if needed) and behavioral mechanisms (reinforcement of continent bowel movements). Randomized clinical trials (RCTs) of MIE have demonstrated feasibility, acceptability, and efficacy for improving encopresis with minimal side-effects when implemented in a specialty clinic with trained therapists. Unfortunately, this service model poses access barriers - especially for children in rural areas. This study aims to address these research gaps by assessing the progression from urine treatment to BM continence and evaluating a novel caregiver-mediated service model of MIE (CM-MIE) to improve accessibility. We will recruit two groups of participants: (a) autistic youth with both enuresis and encopresis and (b) autistic youth with encopresis alone. Those with both enuresis and encopresis (N=70) will enter a pre-randomization phase consisting of enuresis treatment and a monitoring period to assess fecal continence. This pre- randomization phase will allow determination of what proportion of youthbecome continent for bowel movements following enuresis treatment without additional intervention and how long after enuresis treatment this fecal continence emerges (Aim 1). We will also analyze participant characteristics that might relate to acquiring fecal continence in this phase (Aim 2). Those who continue to experience fecal incontinence in the pre-randomization period will join the participants who entered the study with encopresis alone and enter the randomized phase of the study (N=60; 30 per group) comparing CM-MIE to a parent education (PE) program focused on encopresis. Outcomes of the RCT (Aim 3) are the Clinical Global Impression – Improvement Scale rated by a treatment- blind Independent Evaluator and caregiver stress measured by the Caregiver Strain Questionnaire. An exploratory aim will evaluate participant characteristics that impact response to encopresis treatment. This innovative study will be the first to evaluate the progression from enuresis treatment to fecal continence in well- characterized autistic youth and the first to evaluate a caregiver-mediated intervention for encopresis.