Historically, the brain-gut connection has been connected with more "functional" conditions, such as Irritable Bowel Syndrome or Functional Dyspepsia. Functional conditions are a class of disorders that are caused by problems with how the digestion system functions (see, medicine isn't all convoluted all the time), typically at the neurological or muscular level.
When a person with IBS has a colonoscopy, there is no evidence of inflammation either visibly or under the microscope when biopsies are taken and analyzed. Their colon looks like that of a healthy person, even though they may have chronic abdominal pain, bloating, diarrhea, or constipation.
|Isn't that pretty?|
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If you think about it, the brain-gut connection is part of our everyday language. "Gut feelings." "Gut-wrenching." "Butterflies in my stomach." Stress and emotions have a direct, and considerable, effect on our digestive system. The gut has been called our second brain and is run by something called the enteric nervous system. This system contains over 100 million neurons (more than are in your spinal cord or peripheral nervous system). It also contains more of a chemical called serotonin than your brain (95% of it is in your gut, not your head). You may have heard of serotonin as a chemical that's too low in people with depression.
|Schematic of the BGC|
|Captain Caveman had to have had digestive problems.|
|Who is Margret, and why are we always telling her to "punch it!"?|
As I previously mentioned, there's some debate among gastroenterologists if a person with IBD can go on to develop IBS so they have both conditions. Typically this idea is floated when an IBD patient comes to the doctor's office with symptoms but their bloodwork and colonoscopies are clear. How frustrating, right?
At first I thought this was a silly idea, but as I thought about it and read the research, it makes some sense. Chronic inflammation from IBD causes damage that you would think would affect the enteric nervous system, somehow. Also, if stress has a direct effect on the functioning of the digestive system it would make sense that symptoms like diarrhea, pain, or bloating could be from this brain-gut connection and not an IBD flare. It's tricky for patients and physicians to tease this out when the typical "red-flag" IBD symptoms aren't present.
I hope my 2 posts on stress and IBD have been informative. For Part 3, I'd like to get reactions from people about these stress theories. Do you agree? Disagree? What has your experience been with stress and your IBD symptoms? It'll probably take me a few days to get feedback, so Part 3 will hopefully happen in the next week or so.