No, gastrointestinal symptoms are not a sign that autism is environmentally caused

21 Jan

There is a great deal of misinformation in the vaccines-caused-an-autism-epidemic message. The most commonly discussed misinformation is the fear that is spread about vaccines. But there is also a great deal of misinformation about autism causation and biology. For example, it is often stated that environmentally derived disabilities can be treated and that genetically derived disabilities can not. Some of the recent proposed treatments for autism have come from studies of fragile-X syndrome (a genetic condition with a high prevalence of autism). People with Down Syndrome are living longer and more healthy lives due to improvements in treatment. Another misunderstanding that get promoted is that co-morbid conditions, especially gastrointestinal symptoms, in an individual indicate that his/her autism is a result of environmental influences. Much of this impression likely results from the work of Andrew Wakefield, who tried to tie autism, GI disease and the MMR vaccine together.

While it has been long known that this “GI disease means environmental causation” idea is false, a recent paper helps to illustrate that. Gastrointestinal problems in 15q duplication syndrome discusses how gastrointestinal problems are very prevalent in individuals with the genetic 15q duplication syndrome. 15q duplication syndrome, like fragile-X, is a condition with a high prevalence of autism. About 80% of people with 15q duplication syndrome have GI problems, and this number is the same whether or not the individuals also have an autism diagnosis.

Chromosome 15q duplication syndrome (Dup15q syndrome) is a neurodevelopmental disorder involving copy number gains of the maternal chromosome 15q11.2-q13 region, characterized by intellectual disability, developmental delay, autism spectrum disorder (ASD), and epilepsy. Gastrointestinal (GI) problems in Dup15q syndrome have been reported only rarely, mostly focused on neonatal feeding difficulties. A retrospective review of the medical records of 46 patients with Dup15q syndrome was conducted to assess GI issues and their treatments in this population. GI symptoms were present in 76.7% of subjects with an isodicentric duplication and 87.5% with an interstitial duplication. There was no clear association between GI issues and ASD, with symptoms occurring in 78.9% of all subjects and 78.2% of ASD subjects. The most commonly reported symptoms were gastroesophageal reflux (56.7%) and constipation (60%), with 30% of subjects reporting both. The most common treatments were polyethylene glycol for constipation and proton pump inhibitors for reflux. Behaviors such as irritability and aggressiveness improved with treatment of GI symptoms in several subjects. The results indicate that GI symptoms are common in Dup15q syndrome and may have an atypical presentation. Diagnosis may be difficult, especially in individuals who are nonverbal or minimally verbal, so increased awareness is critical for early diagnosis and treatment.

Genetic conditions are frequently multisystemic. Consider Down Syndrome:

People with Down syndrome have an increased risk for certain medical conditions such as congenital heart defects, respiratory and hearing problems, Alzheimer’s disease, childhood leukemia, and thyroid conditions. Many of these conditions are now treatable, so most people with Down syndrome lead healthy lives –

It seems to be a relatively small point I know. It is a topic that I see come up a great deal. And given the guilt that is instilled in parents and the way that the vaccine-causation idea is used as a hook for people selling useless and often risky alternative treatments, it really isn’t such a small point.

By Matt Carey

10 Responses to “No, gastrointestinal symptoms are not a sign that autism is environmentally caused”

  1. lizditz January 21, 2015 at 06:17 #

    thank you Matt. I do not think these points are small at all.

    The myth that “environmentally derived disabilities can be treated and that genetically derived disabilities can not” is extremely damaging and should be firmly laid to rest.

    Trying to get at the root of GI distress or malfunction should not be tangled up with a person’s neurological state, whether autism, ID, or both.

    Untreated GI challenges, such as constipation, have tremendous negative impact on quality of life, as Clay Jones pointed out at Science-Based Medicine last week. (

    • Lawrence January 21, 2015 at 10:05 #

      The vaccine-causation argument (or anti-vax) for autism continues to ignore simple facts like Matt has stated above.

      Genetic conditions like Down’s for instance, have higher rates of birth defects, so understanding the genetic conditions, like gastro-intestinal conditions, that occur concurrently with autism is both a logical and biologically feasible conclusion, unlike trying to blame vaccines for everything.

    • Todd W. January 22, 2015 at 03:58 #

      Liz, I was going to mention Clay’s article, as well. I wonder how much of the GI issues found in people on the autism spectrum has to do more with the sensations associated with bowel movements?

  2. Evelyn Blancaflor January 22, 2015 at 00:40 #

    Autism is not caused by Vaccines, just coincidence. Autism is environmental as it is caused by starvation of either oxygen, glucose and/ or nutrients. Intraventricular hemorrhage and Hypoglycemia in the new born on normal and term babies that were not detected or treated or taken for granted were the causes of all the lifelong neurodevelopmental disabilities. Hypoglycemia in the newborn had been recognised by doctors for mor than 70 years to cause neurodevelopmental disabilities but studies are scarce not like Prematures! Why not research and study all these babies who were normal but stayed few days in the hospital due to some Resp.. Problems, jaundice , low glucose, poor feeding or poor suck, lethargy, low temperature, dark colour, not active, low heart ,rate, jitteriness, etc….costipation and bowel leakage were symptoms.that follow …gastrointestinal issues have connections with neurotransmitters…

    • Ganondox January 22, 2015 at 03:43 #

      ” Autism is environmental as it is caused by starvation of either oxygen, glucose and/ or nutrients. ” No it is not.

    • lilady January 23, 2015 at 21:20 #

      Evelyn, all those signs of fetal or newborn distress are monitored with blood tests and pulse oxymeters during labor, at delivery and in the newborn nursery.

      Intraventricular hemorrhages “taken for granted”? That’s nonsense and newborn jaundice is monitored constantly and for the most part is the normal physiological response as the newborn switches from fetal circulation/oxygenation to breathing. Infant bilirubin levels are caused by the breakdown of RBCs and when bilirubin levels are high they are treated very effectively.

      My baby was born with a rare genetic disorder and he had many of those signs/symptoms. He was hospitalized in the NICU for 10 weeks and required around-the-clock care. As I made the rounds to specialists who cared for him, you better believe I had the complete hospital records for him. If I didn’t have those records, I signed hospital records release forms for the doctors.

  3. Seth Bittker January 22, 2015 at 17:20 #

    Hi Matt,
    I agree with you that genetics significantly impacts gastrointestinal symptoms and there are a number of known genetic disorders that predispose individuals to gastrointestinal disease as well as autism. However, there also is evidence that the prevalence of gastrointestinal disease and dysbiosis in general is increasing and that a significant portion of this increase is real. Given the fact that autism frequently has a gastrointestinal component, I think it is not unreasonable to think that the same may be true of autism. In addition as human genetics do not change rapidly, this points to an environmental contribution to the increase in autism rates.
    Gastrointestinal disease that have increased substantially in recent decades include ulcerative colitis and celiac. Some evidence highlighting that much of the increase in gastrointestinal diseases and dysbiosis is real:
    1) By looking at historical blood samples and comparing them to more recent blood samples in similar populations, celiac disease based on serology has increased by at least a factor of 4 between about 1950 and early 2000s in the Midwestern part of the United States.
    2) Increasing incidence of and virulence of clostridia infection rates. Based on culture testing the evidence points to an increasing virulent strain of clostridia.

    • lilady January 23, 2015 at 21:38 #

      I think you ought to read the blog post written by Dr. Clay Jones, which Liz Ditz linked to; I was blown away by the percentage of N-T kids who have no bowel disorders, yet have problems with bowel evacuation.

      Your second link leads to an article about the problems with the emergence of virulent strains of C. diff infections which are mainly hospital acquired. I didn’t see any mention of healthy non-hospitalized children/adults diagnosed with ASDs.

      • Seth Bittker January 25, 2015 at 01:38 #

        Hi Lilady,
        On perusing Jones’ article that you mentioned, I don’t see a lot of specifics. I did see the statement, “True constipation is very common though, with as many as a third of children affected at any given time, and related complaints from kids and caregivers are the impetus for 3-5% of pediatric sick visits…” I have no idea where he got this from as it does not appear that he has provided a citation. The first figure sounds high to me, and if it is true, it seems that a huge number of people are poorly adapted to their existing environments.
        Independent of Jones’ view, gastrointestinal symptoms are much more common in autism than in controls. These researchers found in autism a 3.63 odds ratio for diarrhea and 3.86 odds ratio for constipation relative to neurotypicals. Separately other researchers found 79% in a population with autism had gastrointestinal symptoms.
        If you dig into papers on autism biochemistry one can obtain additional evidence that gastrointestinal dysfunction is much more common in autism than controls. For example Yap among others has found high levels of hippurate and phenyacetylglutamine in urine of those with autism relative to controls and these are often indictators of dysbiosis. These researchers among others found that markers for clostridia were far more common in autism than in controls.
        With respect to the last citation I provided in the previous post being primarily about clostridia in hospitals, you are correct. Here is another citation which also focuses primarily on the increased rates in institutions but provides additional evidence for significant increasing prevalence outside of them: To be clear neither of these citations mention autism. But what they do show is that the strains of clostridia are changing, clostridia is becoming epidemic in many institutions, and clostridia prevalence is increasing significantly in the general population. When you combine this with the fact that clostridia is extremely common in autism relative to controls, it suggests that there may be a connection between increasing prevalence and virulence of clostridia and increasing prevalence of autism.


  1. How A Child Develops – Development Delay – How Kids Develop | Early Childhood Parenting - January 21, 2015

    […] No, gastrointestinal symptoms are not a sign that autism is environmentally causedLeft Brain Right Brain, on Tue, 20 Jan 2015 21:24:55 -0800Chromosome 15q duplication syndrome (Dup15q syndrome) is a neurodevelopmental disorder involving copy number gains of the maternal chromosome 15q11.2-q13 region, characterized by intellectual disability, developmental delay, autism spectrum disorder … […]

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