GI, Stress, and Autism: Connections through "The Second Brain"
Gastrointestinal (GI) distress is common in autistic children with close to one quarter having at least one chronic symptom (Molly and Manning-Courtney, 2003). Some of the symptoms that occur in greater frequency for this group include diarrhea, constipation, and abdominal pain (McElhanon, et al, 2014). Anxiety is also elevated in autism and this heightened state of distress occurs across the full age range. Research has shown, for example, that children on the autism spectrum are more likely to suffer from anxiety with close to 40 percent having at least one diagnosable anxiety disorder (Van Steenel, Bögels, & Perrin, 2011). Given that both anxiety and GI problems are high in autism, it’s interesting to ponder whether or not there is a link between the two. Research suggests that there is. Mazurek and colleagues (2013), for example, found that autistic children with GI conditions had higher rates of both anxiety and sensory over-responsivity. There may be common underlying mechanisms that are unique to autism that influence the association between anxiety and GI problems. Some areas of the GI system which have been found to be impacted in autism include:
Increased intestinal permeability
Altered intestinal microbiota
Altered Serotonin metabolism
However, it is important to note that the association between emotional distress and GI symptoms also exists for those who are not autistic. There is an increasingly growing body of literature demonstrating a relationship between emotional distress and GI symptoms for the population at large. In some ways, this is not surprising given the multiple ways in which the GI tract and nervous system interact. The interactions between the GI tract and the nervous system are so close that the gut is sometimes referred to as “the Second Brain”. The relationship between autism, GI functioning, and response to stress is a complex and dynamic one. The GI vulnerabilities that have been found in autism may influence and attenuate the response of the GI system to emotional distress. This may make the connection between emotions and GI functioning even closer in autism than in the rest of the population. However, more research is needed. Behavioral factors may also contribute to GI symptoms in autism. Toileting fears, for example, can lead to withholding of stool which, in turn, may lead to constipation and abdominal pain. Dietary behaviors associated with autism (particularly restricted eating) may also contribute to GI problems.
While the search for answers continues, the following are some recommendations that parents and healthcare providers can act on now:
Be aware that GI symptoms are common in autism. For those who are more verbal, be sure to ask about discomfort. For less verbal children, look for behavioral and physical signs of GI distress. Be sure to address any concerns with your healthcare provider.
Given the link between emotional distress and many GI conditions, providing ways to reduce stress and anxiety can be part of the overall treatment plan for both emotional and physical health. Children on the autism spectrum can learn and benefit from a range of relaxation techniques. Providing supportive and accepting environments can also go a long way toward reducing stress.
Be aware of the potential impact of behavioral patterns (e.g. stool withholding, restricted eating) on GI health. Seek consultation when these behavioral patterns impact on health and well-being.
For Ways to Reduce Anxiety for Kids on the Autism Spectrum See My Resources
References McElhanon, B. O., McCracken, C., Karpen, S., & Sharp, W. G. (2014). Gastrointestinal symptoms in autism spectrum disorder: a meta-analysis. Pediatrics, 133(5), 872-883.
Molloy, C. A., & Manning-Courtney, P. (2003). Prevalence of chronic gastrointestinal symptoms in children with autism and autistic spectrum disorders. Autism, 7(2), 165-171.
Mazurek, M. O., Vasa, R. A., Kalb, L. G., Kanne, S. M., Rosenberg, D., Keefer, A., ... & Lowery, L. A. (2013). Anxiety, sensory over-responsivity, and gastrointestinal problems in children with autism spectrum disorders. Journal of abnormal child psychology, 41(1), 165-176.