Jan 05 2010

No Evidence for Autism Associated GI Disorder

Published by under autism
Comments: 18

In a recent supplement of the journal Pediatrics is published the report of a consensus panel on the issue of gastrointestinal (GI) disorder in children with autism. This is not a new study and no new evidence is presented – it is a systematic review of the literature by 28 experts from various disciplines. These formal expert reviews are often a helpful way to make sense of a large and complex medical literature on a specific question.

The most significant finding of the panel is that:

The existence of a gastrointestinal disturbance specific to persons with ASDs (eg, “autistic enterocolitis”) has not been established.

In addition they found that there is no evidence for benefit from special diets. About 1 in 5 children with autism are on a special diet designed to improve the symptoms and outcome of autism, usually by removing gluten or casein from the diet, but there is simply no scientific evidence that such diets are helpful.

The alleged link between GI disorder and ASD was started by the now-discredited study by Andrew Wakefield in 1998. He proposed a “leaky gut syndrome” that allowed the measles vaccine to cause an infection which eventually led to the brain damage that causes autism. His research was later refuted and he is now even suspected of fraud. But the idea that GI disorders contribute to ASD was out in the public and took on a life of its own, separate from scientific evidence.

Now, more than 10 years later, the evidence is largely against the notion that there is a GI condition specific to ASD. But the report is also careful to point out that there is insufficient research to rule out such conditions either. This reflects the usual conservative style of such scientific writing. One of their bottom-line recommendations is for more research in this area – not necessarily to explore the possibility that a GI disorder causes autism, but rather what spectrum of GI disorders are seen in children with ASD and do they require any special treatment or diagnostic approach.

For professionals the panel recommends that they approach a child with ASD and GI symptoms as they would any other child – meaning that children with ASD deserve the same diagnostic workup as any other child with similar symptoms. They do not require any special workup, but neither should their GI symptoms be ignored. They further recommend that special intervention may be necessary for the behavioral consequences of GI symptoms when they do occur. When a child with ASD does have a GI disorder, the pain and other symptoms may trigger problem behavior, and therefore special care may need to be taken not only to treat the GI symptoms but to mitigate the negative effect on behavior.

For professionals and for parents the panel concludes that there are no special diets that have been shown to be of benefit in children with ASD, despite anecdotal reports. Further, children on special diets may be at risk for malnutrition, and therefore nutritional status needs to be assessed.

This is likely to be the most controversial aspect of the report in the autism community. Parents who have observed anecdotally that their child’s behavior improves on a special diet are unlikely to be swayed by a scientific analysis. There is insufficient evidence to rule out an effect, but there is also good reason to be skeptical of the anecdotal reports. It is true that parents intimately know their own children, but this familiarity does not protect them from the powerful effects of confirmation bias.

We have been here before – with alleged food allergies, and the whole sugar causes hyperactivity myth. Confirmation bias is the tendency for uncontrolled observations to confirm what is already believed or suspected. It is largely why we need blinded and controlled observation. For example, people tend to observe and remember those incidents that confirm their beliefs, and ignore or dismiss those that would contradict the belief. It is subtle and subconscious, and impossible to filter out completely just by conscious effort.

Also, there is a tendency to look for confirmation. For example, when a child is hyperactive or exhibiting bad behavior the parent may ask – what did they eat recently? They will look for, and potentially find, an offending substance (sugar, gluten, dairy, whatever) and this will confirm their belief that the food causes the behavior. However, if they do not find an offending substance, this is a non-event and it does not register with them and is soon forgotten. Even more subtle is the fact that the parents will not ask the question – what did my child eat recently? – when they are not misbehaving. And so they will not be aware of the fact that the probability they had the alleged offending food is the same, regardless of the child’s behavior.

This is the exact same psychological factor that leads to superstition, to sports myths, and to the common belief in the lunar effect. I have personally witnessed ER staff look up from their busy work and say, “The ER is crazy tonight, is there a full moon?” The answer on that occasional was “no,” and so they quickly forgot the thought. But when the answer is “yes” it is remembered as powerful confirmation of a lunar effect. Meanwhile, controlled observations clearly show that there is no lunar effect – it is all an illusion.

But humans appear to be hard-wired to be powerfully compelled by their own confirming observations, and it is difficult to impossible to convince someone with scientific data that their personal observations were misleading. This effect is exacerbated by the strong emotional attachment of a parent to their child (a connection of which I am personally aware and completely understand) – and the overwhelming feelings of protectiveness.

This is all the more reason for the medical community to give objective information to parents, and this panel report will be extremely useful in making recommendations for today but also pointing the way to future research. But this only helps when there is a baseline respect for science and the institutions of science.

18 responses so far

18 thoughts on “No Evidence for Autism Associated GI Disorder”

  1. provaxmom says:

    I was pleased to see this in the mainstream media as well. What’s really laughable–go to abc news and look at their interview with JM on this. I don’t know how often she’s going to get b!tch-slapped with science and still continue to try to sell this gfcf diet. I love her clip about “until doctors start listening to moms and their anecdotes….” what she totally doesn’t get is that doctors ARE listening, hence the studies. Just like they listened when you voiced your concerns over vax.

    Doctors and researchers DO listen to nutjobs like her, and as a result, funding goes into studying the same thing over and over and over and over……how many more studies do you want?

    Here’s the clip:

    I’ve seen other clips of her house and her son. She has a whole mini-classroom set up in her house just for him and she pays for all sorts of therapists, ABA and teachers to come to her home for him. If I was them, frankly I’d be pissed off that she doesn’t give them any of the credit for his performance–according to her it’s all because she put him on gfcf and stopped vaxing him.

  2. DevoutCatalyst says:

    Gluten free diets aren’t exactly a piece of cake to adhere to. Yuck, who wants the social limitations of a special diet that won’t permit you to eat real food with your peers? Maybe when the leaky gut and gluten free ideas were thought to be going nowhere, a new market had to be found — victims that couldn’t so readily vote with their forks.

  3. Scott Young says:

    I saw the ABC news clip last night and nearly had my own GI eruption. When will the news media stop being part of the problem!? Why is the scientific method so foreign to them…anecdotes, arrgghh…

  4. superdave says:

    You could do a whole week on GI related pseudoscience. It’s such a simple system to manipulate and observe that it’s a ripe target for bogu… umm, nonscientific treatments.

    I do think it’s plausible that asd children with uncomfortable gi symptoms may be unable to communicate their symptoms well and thus be aggravated. Improving the diet of these children will improve behavior in this situation but this is only superficially related to the asd and in no way treats an underlying cause.

  5. superdave says:

    To clarify what I said, there must be some ASD children who actually do have severe food intolerance such as gluten or lactose and changing the diets of these children is certainly a good idea.

  6. superdave says:

    here is the age of autisms blog headline for their story on this report

    “Pediatrics Consensus Articles Acknowledge Need to Improve Evaluation and Treatment of GI Disorders in Autism”

  7. shawmutt says:

    Hey Steve, you wrote “About 1 in 5 children with autism are on a special diet designed to improve the symptoms and outcome of autism, usually by removing gluten or casein from the diet…”

    Do you happen to have the source for this statement? A couple I’m friends with has an autistic kid, and they refuse to get their second child vaccinated, and claims that she has celiac disease and can’t have any gluten. While I have always been wary of the self-diagnoses, I wasn’t aware of the connection.

    We have had a few heated arguements on the issue (mostly because I really don’t want their non-vaccinated kid around my toddlers), and the more info I have the better. The arguments usually always end with “you can’t know how we feel, you don’t have an autistic kid!” but I feel like I’m planting that little mustard seed.

    Recently they asked me about the H1N1 vaccine, which I was able to explain to them. They seemed to listen a bit more openly, especially since my family got the vaccine even after we may have had the actual flu!

    Love the blog, keep it up!

  8. Steve Page says:

    superdave, their story is even worse than that headline. It’s almost a satire on how to misunderstand and misrepresent a scientific paper; I don’t think that I’d have been surprised if I’d found that it had been crossposted in The Onion.

  9. KathyO says:

    The problem is that these parents are desperate, especially the ones with low-functioning kids. It’s bad enough when the kids are small, but how do you prepare kids who can’t even speak for adulthood? More to the point, what wouldn’t you do, if it might give them some semblance of normalcy? It’s infuriating that the desperation of parents is preyed upon.

  10. Hector Morales says:


    Are you there Washington? Okay.

    Good evening ladies and gentlemen,

    I greet you tonight in the name of the defense of our nation. Given the unparalleled threat to our nation’s well-being, I have just now officially authorized the formation of a new department. I, in cooperation with the leaders of both parties, have established a bold and daring program to eliminate the ever increasing dangers we face from psychiatrists, psychiatry and the psychiatric community and anyone else who actually believes “mental illness” is real, and subscribe to prescribing toxic toxins to cure them.

    For this noblest of causes, we have prepared a massive, clandestine, batch of boobs, our nation’s finest, to engage the enemy.

    To this end, I have signed a special order directing all shrinks, shrinkers, and those even considering shrinking, and anyone who appears to look, act or think like a shrink, to surrender immediately, or else.

    Under the just ratified 28th. Amendment to our Constitution, The Freedom from Those Idiot Psychiatrists and All of the Complete Boobs Related Thereto, Act, our elite coalition of heavily armed sleuths will have full authority to send each suspect directly to CERN for some high speed, experimental, proton collision therapy.

    Habeas Corpus is suspended until further notice.

    Anyone spotted, or suspected of, behaving overtly or covertly whacky, nutty, disturbed, ridiculous, weird, hyper, hypo, all broken up, babbling, bothering others, staring off into space, or, you know “a little out there,“ etc., etc., shall be taken to the homes of, and shall be adopted by, the proponents of this action.

    Together, we shall succeed.
    Together, we shall defeat this enemy of everything we, as Americans, cherish and hold close to our hearts.

    God bless you.
    God bless America.
    Good night.

  11. HCN says:

    Hector Morales said “Are you there Washington? Okay.”

    What about the state of Washington?

  12. DanielleS says:

    That ABC video sure was… something. ”Every parent will tell you something different that helped their child. But all we know from this community is that we do see positive changes from this diet.”-Jenny McCarthy. So let me get this straight: parents aren’t actually trying the same diet “therapy”, but they’re all seeing positive results. Yeah. no way that’s conformation bias right there.

    I also love how ABC decided to interview McCarthy, rather than an actual doctor. Well, actually, it makes me sad and angry, but you get the idea.

  13. eiskrystal says:

    I thought it was “E-numbers” that caused hyperactivity. The huge amount of sugar in the drinks just helped turn them into little energiser bunnies.

    Or is sugar the new E-number?

  14. cyberdraco says:

    Mr. Novella is on NPR http://www.npr.org/templates/story/story.php?storyId=122256276

    “The study may be most interesting because it did not find any environmental explanation for higher autism rates, says Steven Novella, a neurologist at Yale University.

    “You can’t prove a negative,” Novella says. But the results of this and other studies suggest that “if there are environmental factors, they’re small,” he says.”

    I appreciate the communities dedicated work to not only moving forward with effective treatments, but showing how irresponsible beliefs in pseudo-science is dangerous.

    I just started working with my cities’ after school program for elementary school children. Our training teacher for disability awareness said ” I’ve heard all kinds of things say to cause autism from vaccines to the bpb in water…” I stop her there and go ” There have been no scientific studies that show any link to vaccines and autism.” I also started to talk about studies that are starting to identify genetic links in parts of the spectrum but she started talking about something else-good for her sake.

    The big problem the anti-vaxxing community fails to realize is that even IF the preponderance of evidence didn’t show the non-existent link, they are not helping the people dealing with their disability. Demanding ‘green vaccines’ does nothing to facilitate or improve care and wastes time which we don’t have.

  15. nickshakra says:

    Speaking of scientific evidence, ABA therapy is the only method of autism treatment scientific evidence proving its effectiveness. More parents without access to a BCBA therapist can try online services like rethink autism http://bit.ly/6s1G3J with a monthly subscription they offer over 400 aba based video lessons with curriculum support and progress tracking. Good luck!

  16. superdave says:

    as predicted, the age of autism mistakes normal scientific conservative language for admission of lack of proof.


  17. AF_brooklyn says:

    With all do respect, I beg to differ but what do I know, I’m just one of those desperate Autism moms clearly being prayed upon. But don’t take my word for it, perhaps take theirs. Funny how science changes things in a couple of years.


    Impaired Carbohydrate Digestion and Transport and Mucosal Dysbiosis in the Intestines of Children with Autism and Gastrointestinal Disturbances.

    “These results indicate a relationship between human intestinal gene expression and bacterial community structure and may provide insights into the pathophysiology of gastrointestinal disturbances in children with autism.”

    So if a subset of Autistic children have difficulty digesting Carbohydrates, interesting. Then could it be possible they might likely benefit to some degree from a GFCF diet? Interestingly enough I don’t have my child on this diet. I did take her off all dairy 4 months ago, which immediately cleared up all of her eczema, watery eyes, postnasal drip that had plagued her since birth. She was clearly intolerant, but lot’s of toddlers are and grow out of it. Only it didn’t change her chronic diarrhea. I took her off sugar and replaced even watered down juice with water only. I began to see even more improvement in her stool and behavior and focus. Bring down the inflammation a bit, you feel a little better.

    What bothers me most about your post and the subsequent self-involved comments that followed it, is the absolute arrogance in assuming that anyone who tries anything dietary or believes in anything beyond ABA therapy is either some Anti-Vaxx crazy or a desperate naive Mom who doesn’t know any better, fooling herself into believing things work when they don’t.

    The bottom line is, Science doesn’t know what the exact cause of Autism is for every child. What they do know is that there are hundreds of genes associated with it and multiple ways in which these genes can be mutated to create varying degrees of Autistic traits. This tells me that how one person became Autistic is very likely to be completely different than another. Which accounts for why Autism is on a Spectrum. From what I read it seems like Science is actually beginning to validate many of treatments parents have been trying and swearing by for years. Many of these kids have incredibly deregulated immune systems which leads to widespread inflammation throughout the body. What as a parent are you supposed to do when the Science isn’t there yet to address that? Sit back and hope ABA fixes everything? How open to learning would your mind be if you felt like sh*t everyday, couldn’t sleep at night, felt overwhelmed by the sounds, smells, sights and textures around you? Many of these kids have underlying GI issues because there have been genes discovered since this post that are connected to both Autism and GI dysfunction.


    “Independent studies have shown that the MET gene product, a receptor tyrosine kinase protein, functions in both brain development and gastrointestinal repair. These data suggest that altered MET expression may contribute to a syndrome that includes autism and co-occurring gastrointestinal dysfunction.”

    You posted this is 2010 and look at what Science has discovered since, but hey even before your post.


    So how is your post any less irresponsible than the crap Age of Autism puts out sometimes? You don’t know what you don’t know. Maybe you should focus on keeping an open mind when it comes to Autism and inviting a spirit of collaborative thinking. And instead of placing your focus on vilifying a certain group and dismissing another, perhaps you might focus instead on what might actually be causing Autism. Because I guarantee it’s pathology is not so black and white and therefor it’s treatment should not be either.

    I’m not a scientist, an Age of Autism follower or a Jenny McCarthy warrior. I’m a mother to a beautiful little girl who happens to have Autism. It’s changed my life and the those around me to a degree most people can not even begin to imagine unless they are parent to a child with Autism. I will never give up on my kid.

Leave a Reply