In the last 6 years spent researching Crohn’s disease I have come across peer-reviewed medical research connecting inflammatory bowel disease (IBD) — including Crohn’s disease and ulcerative colitis — and autism. Interestingly, it seems as if children with autism spectrum disorders (ASD) are more likely than their peers to also have formal diagnoses and prescriptions to treat IBD. Possibly, the diseased bowel of IBD sufferers lets through neurotoxins that poison the brain causing autism and ASD.
Another study suggests that mothers with autoimmune disease disproportionately produce offspring with ASD, specifically autistic male offspring, while female fetuses of autoimmune mothers die. The idea there appears to be that autoimmune mothers produce anti-brain antibodies that attack the proteins in the brains of the developing fetus; for some reason, the male fetuses live and are born brain-damaged (read: autistic) while the female fetuses of autoimmune mothers are spontaneously aborted. Of course, female autistics and ASD sufferers do exist, but where do they come from? Not from autoimmune mothers apparently. This in-utero brain damage is a similar (but not identical) mechanism to that which is thought to cause brain damage from neurotoxins poisioning the brains of bowel-compromised IBD patients. And even though female fetuses are normally hardier than males, according to the linked study, female fetuses that are poisoned this way tend not to survive.
It has also been suggested, but is impossible to prove, that autistic behaviors somehow contribute to development of IBD through “picky eating” or other actions that alter the diet or other environmental factors of autistic children compared to their peers.
It is difficult to draw conclusions from the evidence that IBD and ASD are correlated, but it provides good food for thought. And in the food-for-thought vein, for those who are interested, I would like to suggest another avenue of inquiry: the possibility of a shared characteristic and common denominator of IBD and ASD as diseases of malabsorption. Specifically, that IBD prevents absorption and assimilation of nutrients from food, while ASD prevents absorption and assimilation of social and developmental norms.
For those who are interested in what is known and/or knowable about autism and the correlation between IBD and ASD, you may wish to stop reading here and start Googling. For my purposes, I wish to postulate the following extremely offensive and decidedly original idea for those who are interested in that, and while there is certainly room for improvement and/or expounding, the following is as fleshed-out as I am currently able to offer.