This Pediatrics review of autism and gut disorders found higher rates of constipation, diarrhea, and stomach pain among autistic people. But the authors do not once mention anxiety.
That in spite of the fact that anxiety is a key feature of autism and that research suggests that autism and anxiety are indeed linked. And that gut conditions like diarrhea and constipation and gut pain are often related to anxiety.
When children aren’t autistic and they have stomach pain or constipation or diarrhea, the frequent conclusion is that stress and anxiety are the cause and predictive of anxiety in adulthood. Indeed, with that little nervous system parked there in our gut, it’s no wonder that things get a little seized up and out of rhythm when the rest of us does.
So why is it that no one attends to this clear (to me) link when it come to autistic children? Well, the Pediatrics review by McElhanon et al. happens to cite that reason several times:
Wakefield’s MMR/autism/gut red herring and the subsequent noxious cloud that his fraud (link added 5/2/14) left over any research examining autism and the gut. So we don’t know anything about the real underlying causes of these digestive problems among autistic children. The Pediatrics authors state it unequivocally, as they have done before (link added 05/02/14):
It is clear that greater clinical and research scrutiny is needed to increase awareness on this topic and thus support development of the best standards of care. Previous controversy surrounding the MMR vaccine and proposed causal link between ASD and infection of the GI tract probably deterred investigators from dedicating resources to examine GI functioning in this population while fostering uncertainty in the ASD community regarding the validity of this line of inquiry.