IBS symptoms often develop in patterns that don’t fully make sense.
You may notice bloating, changes in bowel habits, or discomfort that comes and goes without a clear trigger. Diet changes may help temporarily, but the symptoms tend to return.
This pattern is not random.
It reflects a shift in how the digestive system is functioning under stress. When the stress response remains active, digestion becomes less consistent, less efficient, and more reactive.
This page explains how IBS symptoms develop in Adrenal Fatigue, why digestion begins to break down, and what needs to change for that process to stabilize.
How IBS Symptoms Begin Under Stress
Digestion, when functioning properly, is a well-orchestrated process involving the nervous system, digestive enzymes, and stomach acid.
Hydrochloric acid (HCl) production in the stomach is the main stage of digestion. This is where the real work gets done. Strong hydrochloric acid levels are needed to initiate the chemical breakdown of food and to stimulate other digestive processes.
If you are stuck in a chronic stress response, the entire digestive process shuts down, leading to IBS symptoms.
Once released, these digestive enzymes must be cleaved to be activated. That process is also dependent upon hydrochloric acid, which stimulates the gallbladder to produce bile to expedite fatty acid absorption.
The next stage of digestion is the release and activation of the many digestive enzymes required to process various foodstuffs. The pancreas is stimulated by hydrochloric acid to release pancreatic enzymes.
This entire digestive process is designed to take larger foodstuffs and break them down into smaller units for absorption. We cannot absorb protein, carbohydrates, or fat, but we can absorb amino acids, glucose, and lipids.
When your system is in “rest-and-digest” physiology, your entire digestive process is fully turned on and functions smoothly.
But, what happens when we’re stuck in a chronic “fight-or-flight” state, due to Adrenal Fatigue and Stress Response Dysfunction (SRD)?
How Adrenal Fatigue Disrupts Digestion
Believe it or not, your state of mind is crucial in the initial phase of the digestive process.
The mind is so powerful that an insulin release from the pancreas can occur from simply thinking about food.
There are several ways the digestive system is suppressed when we are stuck in a chronic stress response. The systematic shutdown starts with the Autonomic Nervous System (ANS)—the nerve side of the stress response system— and is mediated primarily through the main parasympathetic nerve, aka the vagus nerve.
Believe it or not, your state of mind either helps or hinders the digestive process.
This nerve controls the vast majority of the digestive process, from mouth to anus. But with chronic stress, our body “turns off” the vagus nerve, which then begins to suppress our appetite, salivary enzymes, stomach acid production, as well as restrict blood and nerve flow to the digestive organs.
If you are stuck in a chronic stress response, the stimulation of the digestive process does not get triggered in anticipation of food. Instead, the entire process shuts down before it even starts. So, even though you eat, your digestive fire and all your digestive juices are compromised.
Why the Body Shuts Digestion Down During Stress
I think this makes sense to most people when I explain it this way: If we’re in a stress response, the body is gearing up to fight the proverbial tiger. At that time, you don’t want to waste precious energy digesting and absorbing food. Let’s face it, it’s a bad time to sit down for a meal or have a bowel movement.
Dealing with that “tiger” requires turning the digestive system off temporarily, conserving energy to address the threat (stress), and then, once you’ve survived, turn the digestive function back on.
IBS symptoms often show up alongside other patterns of Adrenal Fatigue that affect energy, sleep, and immune function → Adrenal Fatigue Symptoms
How Diet Patterns Can Worsen IBS Symptoms
One-fifth of our meals in the U.S. are consumed while driving a vehicle. We need to eat but barely have time to shop or prepare a meal for lunch. Fast food has become the quick-fix answer to hunger, and eating while driving is commonplace.
Trying to scarf down a fish sandwich while operating a vehicle is not your ideal rest-and-digest state. You are in a stressed out, fight-or-flight state, doing too many things at once. Trying to enjoy a meal while on high alert compromises your digestion.
One-fifth of our meals in the U.S. are consumed while driving a vehicle.
You’re gulping the food, which is then not being predigested by the salivary enzymes in your mouth. The food enters your stomach, awaiting chemical digestion of hydrochloric acid, which also doesn’t occur. Then, the pancreas is not stimulated, enzymes are not released, and the food is left to ferment and rot.
The rotting food releases organic acids, which are more caustic than hydrochloric acid. The organic acids begin to irritate the digestive mucosal lining.
Since sufficient hydrochloric acid is never secreted, the muscles in the stomach begin the mechanical process of mixing the food around in the little hydrochloric acid that may be there. The physical churning of the stomach may cause it to slide up through the diaphragm. The effects get worse from there.
What Happens When Food Isn’t Properly Digested
The undigested food causes problems every step of the way and eventually may lead to any or all of the following.
- Hiatal hernia
- Gastritis
- Heartburn and reflux
- Ulcers
- Leaky gut syndrome
- Food allergies
- Dysbiosis
- Gas and bloating
- Diarrhea and/or constipation
How Gut Bacteria Become Imbalanced
Eventually, the stomach slowly releases the undigested food into the small intestine where it should begin to be absorbed. But the poorly digested foodstuff is not small enough to be properly absorbed.
In time, this dysfunctional process can cause nutrient deficiencies and irritation of the mucosal lining. The delicate, absorptive small intestine is protected by a Teflon-like lining, only a millimeter thick, which begins to wear. This contributes to intestinal permeability, or leaky gut syndrome, which progresses into the development of food allergies.
Poor digestion causes much of the good gut bacteria to die.
Digested food moves through the intestine by rhythmic muscular contractions called peristaltic waves. This action is anchored in the nervous system, and more specifically by the vagus nerve. In a stress response, the vagus nerve is inhibited.
Once the food finally reaches the large intestine, it is difficult for the good bacteria to process it. It’s too large! It should have been broken down much more by this point.
The lack of proper processing causes some of the good bacteria to die. Then, the problematic bacteria flourish. This occurrence alters the very delicate bacterial balance in the colon. We call this dysbiosis.
A dysbiotic state contributes to a potential condition of yeast or intestinal candida overgrowth. And finally, the stage is being set for the potential development of irritable bowel syndrome. Inflammation of the bowel also contributes to the common symptoms of gas, bloating, diarrhea and/or constipation.
How Digestive Function Begins to Recover
As with the treatment of the immune system, treatment of the digestive system does not start with addressing the digestive process at all.
The first step of healing is getting to the root of what’s inhibiting this delicate process. Symptomatically treating digestive disorders is fine…but it’s not permanent. It may alleviate some unpleasantries, such as heartburn, diarrhea, or belching, but that relief is temporary at best.
If the Stress Response Dysfunction (SRD) and Adrenal Fatigue are not healed at the same time, the digestive issues and IBS symptoms will reoccur.
Stabilizing the stress response system is what allows digestive function to begin regulating more consistently, which is where IBS symptoms start to change → How Adrenal Fatigue Is Treated
