Enteric Nervous System (ENS) | Your Second (Irritable) Brain and IBS

Posted on 0 Comment

Enteric Nervous System (ENS) | Your Second (Irritable) Brain and IBS

If you’ve ever suffered from irritable bowel syndrome (IBS), you know it’s no joke. Cramping, bloating, constipation, diarrhea, and abdominal pain can make your life a living hell and disrupt your day-to-day activities. It’s estimated that about 10-15% of Americans suffer from IBS, which means about one in ten people have to deal with it.

Since it’s so common, you would think there would be more information on it, but researchers don’t know what causes IBS. However, it’s categorized as a neuro gastrointestinal (GI) disorder. This means there’s a problem with how your gut and brain interact.

So, how exactly do the gut and your brain interact? And how does that system break down?

The Enteric Nervous System – Your Second Brain

The enteric nervous system (ENS) (sometimes called the intrinsic nervous system) is a mesh-like system of neurons that directs the gastrointestinal tract (esophagus, stomach, small intestine, colon). Think of it as an intelligent sweater that your GI tract wears.

This intelligent sweater has approximately 500 nerve cells, which, in terms of size, is about the size of a cat’s brain.

Why should you care about how many neurons your gut has? Here’s why:

  • Your enteric nervous system can and does act independently from your brain
  • Your enteric nervous system can have a two-way conversation with the brain (called the “brain-gut connection”) via the Vagus nerve
  • It responds to the food you eat by controlling gut muscles and secretion of a myriad of hormones, neurotransmitters, and beyond!

For this reason, your ENS is commonly referred to as your “second brain.” It’s why you feel butterflies in your stomach, get sick, have diarrhea, etc., when feeling strong emotions or anxiety. Emotional duress in your main brain can carry over into your 2nd brain.

But what does your ENS do? Why are we talking about it? What’s its role with IBS? These are important questions for people who are victimized by an angry bowel.

Role of ENS in IBS and IBS symptoms

The enteric nervous system is immensely complex, and the full scope of its function is not entirely understood. Concerning what we do know, the ENS has several vital functions to point out.

  • Your enteric nervous system chemically and mechanically (physically) senses the foods that you eat
  • Your enteric nervous system (2nd brain) communicates directly with your central brain via the Vagus nerve about foods it senses
  • Communication between the main brain and second brain plays a central role in digestive function and reflex of the GI tract
  • Independent of the central brain, the ENS controls gut muscle movement (i.e., regulates peristalsis – commonly called gut motility, which is the wavelike contractions and relaxations of gut muscles that push food through your gut)
  • Controls secretion of chemicals that digest the food you eat
  • 95% of serotonin and 50% of dopamine live in your gut (please briefly see this link on serotonin function and importance)

What all of this means is that the enteric nervous system is a central contributor to regulating:

  • Anxiety
  • Happiness
  • Mood
  • Sleep
  • Nausea
  • Bowel movements

Now you see why we are talking about your enteric nervous system. For anyone experiencing symptoms of IBS, this list may look uncomfortably familiar. The ENS plays a central role in irritable bowel syndrome and the symptoms of IBS. If you want to know why you experience specific IBS symptoms, the causes of IBS, etc., you need to know about the enteric nervous system – your 2nd brain.

Long story short, while IBS is a blanket term for a wide swath of conditions with several potential leading causes (parasite infections, small bacterial overgrowth syndrome (SIBO), toxic mold syndrome), the primary culprit of IBS appears to be a disruption, miscommunication, fighting, (whatever you want to call it), between the ENS and your central brain. We even have a rather ominous term for it: “enteric neuropathy.”

IBS and the Vagus Nerve

The vagus nerve plays a critical role in regulating the gut-brain connection, and its influence is particularly evident in IBS. As the longest cranial nerve, the vagus nerve is responsible for controlling involuntary digestive system functions, such as bowel movements and the release of digestive enzymes.

Research suggests that vagal dysfunction could exacerbate IBS by heightening the gut’s sensitivity, triggering an overreaction to normal stimuli such as food or stress. Strengthening vagal tone through techniques like deep breathing, meditation, or even vagus nerve stimulation therapies may help alleviate some of these symptoms by restoring balance to the gut-brain axis and promoting more efficient digestion and bowel function.

Do I Have IBS (and What Kind of IBS Do I Have?)

So, without further ado, here are the six telltale symptoms of IBS.

1 – Fecal incontinence and IBS

Fecal incontinence is the inability to control bowel movements. It’s the reason people with IBS have a mortal fear of long car rides, airplanes, long lines at porta-potties, etc.

There’s no downplaying just how embarrassing this problem is for many people (about 2-3% of the population) and what a source of anxiety it is. No kidding, fecal incontinence can be downright debilitating. Not everyone who is taking anti-anxiety pills before flights is doing so because they are scared of heights.

Fecal incontinence can range from:

  • Having trouble “holding it” when the power-movement urge comes
  • Having trouble with a small amount of “seepage” after using the restroom
  • Having little to no bowel control

People who struggle with this tend always to have a mental map of their environment, which includes where the bathroom is and how far away it is at all times.

There are several likely ENS causes of fecal incontinence in people with IBS:

  • Your ENS may stimulate diarrhea to dilute/flush out a perceived threat – it is much harder for your back door to keep in watery stools, meaning people with irritable bowel syndrome diarrhea (IBS-D) tend to be prone to this
  • Your ENS strongly stimulates your urgent need to go RIGHT NOW in response to a perceived threat, and if you’re not near a bathroom when that catastrophic urge hits you…
  • A sluggish ENS that has slow gut motility can result in irritable bowel syndrome constipation (IBS-C) symptoms, which can result in such a backup of poo that fecal impaction occurs. Basically, this means you have a brick of poo stuck in your intestine, and liquid feces can still worm its way around, leading to incontinence.

If you struggle with IBS-D or IBS-C, you very well may have a “faulty switch” in your ENS to blame.

2 – Pruritus ani and IBS

Pruritus ani is a widespread IBS symptom that most websites are reticent to discuss. Unfortunately, the many causes of an itchy butt also tend to be many of the symptoms of IBS, like:

  • Diarrhea
  • Frequent wiping
  • Leakage / fecal incontinence
  • Food allergies/intolerances
  • Hemorrhoids

If your enteric nervous system is freaking out, it can cause spasms in your colon that can make your chocolate starfish itch. If your enteric nervous system is raising the alarm and flushing out your system, it can cause diarrhea, which can irritate your colon.

3 – Proctalgia fugax and IBS

Like the itchy butt symptom, the painful rear symptoms are not symptoms. Most other websites are chomping at the bit to discuss. This is a disservice to readers because proctalgia fugax is a strong hallmark of IBS.

Sudden muscle contractions cause it in your anal canal – muscle contractions that may (likely) be caused by your enteric nervous system.

4 – Ode de Toilette, i.e., rotten-smelling poo and IBS

Using public restrooms can be a significant source of concern for people with IBS.

These fears can be highly embarrassing if they come true – and for many people with IBS, they have come true in the past. Not everyone is taking anti-anxiety pills before an airplane ride because they are afraid of flying: they might just be scared of the “bathroom situation.”

Why can people with IBS have such foul-smelling poos? For one, if your gut motility – which moves food through the colon and is controlled by your ENS – is poor, then food can begin to ferment and rot in your gut. They could also indicate unhealthy gut flora (think Small Bacterial Overgrowth Syndrome).

5 – Small Bacterial Overgrowth Syndrome (SIBO) | IBS’ twin brother

Whether SIBO causes IBS or IBS makes you vulnerable to developing SIBO, the fact is that the two problems go hand in hand. SIBO may be the underlying cause of your IBS. SIBO may be a product of your IBS.

Unlike a formal IBS diagnosis, establishing whether or not you have SIBO is as simple as taking an SIBO breath test. Literally, breathe into the breath test, which can be done at home, and find out if your small intestine is infested with bacteria that don’t belong there.

So, long story short, if you DO have SIBO, there’s a high chance you also have IBS.

6 – Autism and IBS

Of all the symptoms you usually don’t see on other websites, this one is probably the ‘big shocker” that makes you say, “Wait, what?” The CDC recently found that kids with autism are 350% more likely to suffer from GI problems such as diarrhea and constipation [5]. Other studies have found significant differences in the gut flora of children with autistic disorders as compared to neurotypical children.

For more information, see

The basic fact is that having autism makes you more vulnerable to having IBS. If you are on the autistic spectrum, or if you have a child on the autism spectrum, you will need to be vigilant about symptoms of IBS.

What Can You Do About IBS?

Since IBS isn’t fully understood, its cure is also mysterious. Some people have IBS for only short periods before the symptoms seem to disappear magically. Others have more consistent problems, which can last for years. As we wait for a long-term cure, here are some things that can help alleviate the painful, embarrassing, and uncomfortable symptoms of IBS.

Diet and lifestyle for IBS

Treatment plans for IBS aren’t based on curing it but rather on treating the symptoms. Diet and lifestyle changes are often the first line of defense against IBS. Providers usually recommend tracking your diet and cataloging any flare-ups so you can remove the foods that trigger your symptoms.

Cutting out foods that can create irritation is also a good idea. These can include foods that cause gas, gluten, and foods containing FODMAPs (fermentable oligosaccharides, disaccharides, monosaccharides, and polyols).

Medication and treatment for IBS

There are also some more specific treatments based on the specific type of IBS that you suffer from. So, if you struggle with constipation, you can try fiber or laxatives. But if you have issues with diarrhea, your doctor may recommend you take OTC or prescription anti-diarrheal medications.

An alternative mode of attack is through the use of antidepressants. While there hasn’t been much research on the subject, there have been some promising studies. In one study, nearly 500 people took amitriptyline or a placebo for six months, and those who took the antidepressant were twice as likely to report an improvement in their symptoms. You may want to talk to your doctor about this option if you aren’t responding to diet or lifestyle changes.

No More IBS

The connection between your gut and brain, mainly through the enteric nervous system (ENS), plays a central role in the complex and often misunderstood condition of irritable bowel syndrome (IBS). As your “second brain,” the ENS regulates numerous bodily functions that influence digestion, mood, and overall well-being. When this system misfires, it can lead to the uncomfortable and debilitating symptoms associated with IBS.

Understanding the intricacies of the ENS and how it interacts with your primary brain is crucial for managing IBS symptoms. Whether it’s through improving vagal tone, addressing SIBO, or simply gaining a better understanding of your body’s signals, there are steps you can take to regain control of your gut health and, by extension, your quality of life.

If you want more insight into your microbiome, we can help! Our GI-MAP Test Kit can give you a detailed map of your digestive tract. Order a discrete test now!

Health Disclaimer: It is recommended the reader of this site consult with a qualified health care provider of their choice when using any information obtained from this site, affiliate sites and other online websites and blogs. Please consult your healthcare provider before making any healthcare decisions or for guidance about a specific medical condition.

If you are enjoying this article, see these other articles for some more informative and (sometimes) fun information about your health:

Thank you for reading! Your path to enhanced cellular wellness starts here!

Health Disclaimer: It is recommended the reader of this site consult with a qualified health care provider of their choice when using any information obtained from this site, affiliate sites and other online websites and blogs. Please consult your health care provider before making any healthcare decisions or for guidance about a specific medical condition.

Categories : Bowel, Gut Health, Mitochondria, Microbiome, Brain Fog, Anxiety
Tags: , , , ,
Share this on: