IBS and the Three Nervous Systems
The Second Brain
There is an actual physical finding in Irritable Bowel Syndrome (IBS), that indicates that IBS is not “all in the head.” All in the nerves, maybe, but not all in the head.
The Three Nervous Systembs
To begin with, we need to understand that our bodies have three nervous systems:
- CNS - The Central Nervous System
- PNS - The Peripheral Nervous System
- ENS - The Enteric Nervous System, or the “second brain”
The CNS - Central Nervous System - consists of the brain and spinal column.
The PNS - Peripheral Nervous System - consists of the very long nerves that run along our arms and legs to our hands and feet.
The ENS - Enteric Nervous System - is the nerve tissue that lines our gut = the viscera = (mostly) small and large intestine.
And Serotonin
Serotonin is a neurotransmitter that plays an active role in the activity of neurons in the brain (CNS) and in the gut (ENS) . This activity, to simplify it all, either speeds impulses along the nerve pathways, or (as lack of activity) slows down nerve impulses.
Motility and Serotonin
What do you suppose that would do for motility–the ability of the gut to move its contents along easily, nicely, and calmly to the desired end. That’s right. The role of serotonin and the balanced action of serotonin affects both the speed of thought and the motility of the gut.
“Chemical Imbalance”
Depression is the major chemical imbalance in the brain that reflects an unbalanced serotonin activity. Not exactly similarly, just in somewhat the same fashion, IBS (IBS-C and IBS-D) are in part the result of a “chemical imbalance” of the Enteric Nervous System (ENS), the nerves that operate your gut, which rely on serotonin to transmit signals from one nerve ending to the next.
Balancing Serotonin
That’s why a gastroenterologist (gut doctor) may prescribe a tricyclic antidepressant, not because she or he is treating your head or thinks you are depressed. It is, rather, because he or she wants to give your Enteric Nervous System (ENS) more serotonin to work with for a better-balanced ENS.