Related &
Co-Occurring Conditions

Identifying autism

While there is not a single behavioral or communication test that can detect Autism, several Autism-specific tools are now being used for formal diagnosis. These include the Autism Diagnostic Observation Schedule, Second Edition (ADOS™-2), the Autism Diagnostic Interview (ADI), the Screening Tool for Autism in Toddlers (STAT), the Childhood Autism Rating Scales (CARS), and the Tele-ASD-Peds for diagnosis for use in telehealth. All of these tests should be used as part of a larger assessment, and not just on their own, as the determination of Autism is best completed with multiple sources of information.

Medical literature states that about 47 percent of adults who experience Autism and 45 percent of children with Autism have gastrointestinal symptoms. Diarrhea is most common, followed by abdominal pain and constipation. Constipation in people with Autism is usually not hard, impacted stools, but the slow passage of stools with long gaps in between, and loose stools when they do come.
Research studies have frequently used inappropriate IQ tests, such as verbal tests with nonverbal individuals, and in some cases have estimated intelligence level without any objective evidence. Tests that do not require language skills, such as the Test of Nonverbal Intelligence (TONI), can offer more accurate information about the person.
Many people who experience Autism have sleep challenges. Night waking may be due to gastrointestinal issues, allergies, environmental intolerances, seizures or the effects of medications. Other potential causes are sleep apnea (pauses in breathing when the airway becomes obstructed during sleep), sleep terrors or confusional arousals. Individuals with sensory processing difficulties may have more problems falling asleep and increased periods of night waking.
It is estimated that around 30 percent of people with Autism develop epilepsy, some in early childhood and others as they go through hormone level changes in puberty. Suspected seizures should be confirmed by electroencephalogram (EEG) and treated with prescribed anticonvulsant medications.
Children with a dual diagnosis of Autism and a sensory impairment face many possible paths. If the child is born deaf/hard of hearing or blind/visually impaired, that diagnosis is usually made early on, and Autism behaviors may be mistaken for a reaction to the sensory loss. Conversely, if a child with Autism has progressive hearing and visual impairments, his or her adaptation to the sensory loss may be misunderstood as a behavior of Autism. For more information, visit the Nebraska Center for the Education of Children who are Blind or Visually Impaired or this article about Autism and deafness. About 30 percent of children receiving education related to deafness/hard of hearing and blindness/visual impairment are also identified as having Autism. Every child should be able to enter his/her education program in the best aural and visual health possible, and should be monitored and tested to ensure continued health and care. For more in-depth information on hearing and vision screenings for people with Autism, see this article from the Autism Advocate. Families can feel overwhelmed and isolated while searching for information. The Autism Society offers a connection to the resources and support families need.

Increasing evidence shows that gastrointestinal (GI) symptoms, such as gastrointestinal disruption, abdominal pain, diarrhea, constipation, and flatulence, has been characterized as a common comorbidity in patients with ASD, ranging between 9 and 84% depending on the studies being retrospective or prospective (Wasilewska and Klukowski, 2015), and are linked to the severity of ASD symptoms (Adams et al., 2011; Gorrindo et al., 2012; Chaidez et al., 2014).

According to an article published by Frontiers in Neuroscience, scientists widely accept the gut-brain axis theory, which states that the gut and the brain communicate and influence each other (Bienenstock et al., 2015; Mayer et al., 2015; Cryan et al., 2019).

Despite this connection, there has yet to be a proven cause-effect relationship between Autism and GI symptoms. The brain-belly connection of gut microbiota remains an area of research for those concerned with both GI and immune connections to neurological differences and disorders.

Some people with Autism have very high pain thresholds (insensitivity to pain), while others have very low pain thresholds. There are interventions, such as sensory integration therapy, designed to help increase reliability of their sensory processing and integration.

About 30 percent of children with Autism have moderate to severe pica, a compulsive eating-disorder characterized by eating non-food items such as paint, sand, dirt, paper, etc. Pica can be dangerous as ingesting these inedible substances can cause choking, digestive problems, parasitic infections, and other illnesses.

The diagnosis of Autism includes atypical responses to sounds, sights, touch, taste and smells. High-pitched intermittent sounds, such as fire alarms or school bells, may be painful for people with Autism. Scratchy fabrics and clothing tags may also be intolerable, and some people have visual sensitivities, such as the flickering of fluorescent lights.

These are only a few examples of sensory experiences. Sensory needs can range in severity and change over time. Consult an occupational therapist for support in evaluating and supporting sensory processing and integration.

About 30 percent of children with Autism have moderate to severe loss of muscle tone, which can limit their gross and fine motor skills.

Understanding the Dual Diagnosis:
Down syndrome & Autism Spectrum Disorder (DS-ASD)


Recent studies report that about 16-19 % of individuals with Down Syndrome also have Autism . Diagnosis of DS – ASD is more difficult to make in individuals with Down Syndrome , as ASD presents differently in individuals with Down Syndrome than it does in their peers with ASD alone .

A diagnosis of Autism Spectrum Disorder is based on symptoms in three domains : social impairments , communication impairments , and repetive behaviors . Diagnosis should only be carried out by experienced clinicians using standardized assessments and comprehensive evaluations .

Early diagnosis of ASD individuals with Down Syndrome and therapeutic intervention is key to supporting those with DS – ASD.

Therapies for individuals with the dual diagnosis of DS – ASD may include : behavioral / ABA therapy , extensive speech therapy , feeding therapy , occupational therapy , and vision therapy.

Individuals with the dual diagnosis of DS – ASD often exhibit these

  • Develop atypical behaviors early
  • May have associated medical conditions such as seizures and hypotonia
  • Exhibit repetitive behaviors
  • Expressive language is severely delayed or absent
  • Exhibit stimulatory behaviors ( hand flapping , rocking , object fascination )
  • Early developmental regression
  • Exhibit self – injurious behaviors
  • Higher incidence of severe cognitive impairments
  • Higher incidence of severe aggressive behavior

The Autism Society Inland Empire welcomes and supports all individuals with DS – ASD and their families.