Ever had butterflies in your stomach, felt nauseous before an exam, or tired after you eat?
Considered a “complex, integrated brain in its own right”, this system has over one hundred million neurons, more than the number in the spinal cord, located within the lining of the gastrointestinal tract and manages the gastrointestinal tract without the assistance of the cranial brain.
All these feelings of butterflies in your stomach and your gut reactions are functions of this enteric nervous system. Because the neurotransmitters of the brain are also present in the bowels, drugs designed for one tend to affect the other. For example, many patients who take drugs, designed to increase serotonin levels in the brain, also experience gastrointestinal problems like diarrhea or constipation stimulated by serotonin in the ENS (enteric nervous system).
Hopefully that explains a little about how your gut works, it’s a very complex part of your body with many functions and responsibilities. If you would like to read more on this subject we recommend going to this link. The second brain by Michael Gershon