Autism spectrum disorder (ASD) is defined by DSM-V as a common neuro- developmental disorder including deficits in social and interpersonal communication . Vesico- sphincter dysfunction (overactive bladder with urinary incontinence or dysfunctional voiding) is a too common and underdiagnosed condition in ASD patients, accompanied by gastrointestinal complained such as constipation and/ or fecal incontinence (FI). Aims of the study was to evaluate prevalence and types of bladder and bowel dysfunction (BBD) in young and adults with ASD and to assess the impact of neuropsychiatric feature on BBD. A comparison with children/ adolescents suffering from ASD and with a control group of typically developing (TD) subjects has been also carried out.

An observational study was conducted in a single Italian centre. Thirty- five patients (22 adults and 13 children/ teens) with confirmed ASD were recruited enrolled from the inpatient clinic of a specialized Institute. A matched group for sex and age of TD subjects acted as control. At baseline, clinical history and physical examination were collected from the patients’ clinical charts. Subjects underwent a full neuropsychiatric evaluation with: intelligence quotient (IQ) evaluation for intellectual disability (ID) with the Wechsler Intelligence Scale, the validated Italian version of the Neuropsychiatric Inventory Scale (NPI) to identify other psychiatric disorder, the Vineland Adaptive Behaviour Scale 2nd Edition (Vineland-II) to assess patient’s adaptive behaviour. The evaluation of BBD was performed according to the International Continence Society (ICS) standards for adults and the International Children Continence Society (ICCS) criteria for children and teens. A 3- day voiding diary was used to record urinary symptoms and pads usage. Urinary incontinence (UI) was classified as continuous or intermittent, and diurnal or nocturnal UI. Nocturnal enuresis was also recorded. For continent patients who voided spontaneously, parents/caregivers were asked to control the following symptoms: straining, intermittency, hesitancy and post-micturition dribble. Patients underwent also urinalyses and cultures and the ultrasound measurement of post- void residual volume (PVR) after a spontaneous micturition. A 3- day bowel diary was used to assess FI, constipation and the coexistence of both. The relationships between urinary symptoms and neuropsychiatric and adaptive behaviour conditions were examined. The control group underwent the same evaluation.

Thirty- five ASD patients (29 males and 6 females) were prospectively included in the study. Mean age ± SD was 23.1 ± 11 years (22 patients aged  ≥18 years and 13 from 5 to 17 years). 
The results related to IQ are shown in Table 1. Both the Vineland-II 
and the NPI scores showed a severe alteration of adaptive behaviour and neuropsychiatric status in our ADS patients
We did not observe any significant differences between young and adult ADS patients on Vineland-II total score (20.5±2.3 vs 22.0±5.3 respectively, p=0.3). With regards to NPI scores of each individual domain, we did not identify any significant difference between young and adult patients (Table 1). The majority of cases presented with some type of urinary or FI, with continuous incontinence more frequent in young ASD patients, and enuresis more frequent in the adult ones. High PVR (>300 ml) was observed in 4 patients. Equally distributed appeared to be FI and intermittent UI (Table 2). With regard to TD subjects, NPI and Vineland-II scales were within normal ranges; 2 women complained also of intermittent urge UI, and 1 male and 2 females of constipation. No other BBD were detected (Table 2). The following significant relationships have been identified between urinary urgency and some Vineland-II domains, as communication ability (p<0.005), reduced daily living skills (p<0.04), and reduced motor skills (p<0.002). In addition, intermittent and continuous incontinence, enuresis and FI were significantly related with reduced daily living skills (for all the relationships, p<0.01).

In the present study a high prevalence (80%) of BBD has been found in both young and adult ASD patients. While some information exists on BBD in ASD children and teens, no data have been reported until now on the disease in adult patients. Here we show for the first time that adult ASD patients are strongly affected by intermittent urinary and FI, while continuous incontinence is more frequent in young patients. More severe alterations in some adaptive behaviour domains and in intellectual and neuropsychiatric disorders play an important role in determining and maintaining BBD in ASD patients. Probably maturation deficit in the central nervous system may be responsible for the high prevalence of nocturnal enuresis and urinary incontinence, together with emotional problems and reduced attentional performance.

Young and adult patients affected by ASD present with a high prevalence of bladder and bowel dysfunction. These problems are strongly related with intellectual disability, poor adaptive behaviour and presence of severe neuropsychiatric disorders. A shared pathogenetic mechanism could underlies the co-occurrence of ASD, mood disorders and BBD in these patients.