Colonic Inertia
When lack of colonic motility
Leads to intractable constipation

In this article, we take a close look at colonic inertia, also called “slow transit constipation”, which is one of the possible causes of constipation. .

You may have come to this page because you have chronic and severe constipation that doesn’t respond to diet or medication - you are looking for a possible cause. Or you may be one step further, you have been told you have colonic inertia and you’d like to get informed on the subject.

Whatever path brought you here, you’ll find a thorough summary of this frustrating condition. Understanding is always the first step towards resolution.

In this article, we first describe what colonic inertia is, who suffers from it, and how it can be diagnosed. We then present the different options to find relief and hopefully eliminate the problem.

What is colonic inertia?

Simply put, colonic inertia is a functional problem that makes your colon hold on to fecal matter for too long.

If you remember the introductory section of this website, one of the key roles of the colon is to reclaim precious fluids from food residues. In other words, it is a dehydrator. If feces stay in the colon for too long, they end-up too dry, leading to constipation.

So why would your colon hold onto fecal matter for too long?

The colon moves food residues forward from the intestine to the anus using wave-like movements. Those movements happen on a regular basis. The stools are moved forward a bit, then rest a bit to let the dehydration process take place. Then another wave gets them going a bit further, and so forth, until they reach the rectum. Once the stools reach the rectum, the defecation urge is activated.

To generate those wave-like movements, the nervous system sends some electrical impulses to specialized cells in your colon. Those are called “interstitial cells of Cajal”, and they forward the electrical impulse to the smooth muscles of the colon, triggering the contraction.

Some studies have shown that people suffering from this condition have a decrease in the number of those cells(1) compared to healthy patients.

Interstitial Cajal cells are required for normal intestinal motility. Those cells are electrical connections that act as intestinal pacemakers. A lack of these cells in certain areas of the colon means a much slower transit (and sometimes no movement at all in a section of the colon).

Broader neurological issues can also been implicated. The Cajal cells are just the end point of a complex nerve transmission system. Other components of the nervous system, such the enteric nervous system, can be part of the problem.

Some research shows that patients with colonic inertia have other transit disorders touching the many organs managed by the enteric nervous system(2) (esophagus, stomach, gallbladder, etc) - gastroparesis for instance.

What causes colonic inertia?

There are still a lot of unanswered questions about possible causes. However, several hypothesis have been formulated.

Diabetes can lead to a loss in the number of Cajal cells(3). The relationship between diabetes and nervous system damage is well known today.

The problem can be congenital, with obvious repercussions from the beginning of the person's life. If you have congenital colonic inertia, you likely have had constipation issues since you were a kid.

Infectious agents may play a role in the degradation of the enteric nervous system’s functioning as may the balance of intestinal flora(4).

Some women develop slow transit following a hysterectomy or childbirth, which may damage some of the enteric nervous system.

Some doctors believe that continuous and long-term use of stimulant laxatives may worsen this condition and further effect the neurological structures of the gut, although this remains controversial in the scientific literature.

Finally, the aging process, and genetic background may be implicated(4).

Whatever the causes are, the development of this condition is not something you control. This condition may linger since childhood if congenital, or you may have developed it later following an infection or other trauma.

Again, we are not talking about external constipation triggers that you can tweak and change at will, we are talking about internal physiological changes that are now here to stay and need to be dealt with.

What proportion of the population has colonic inertia?

According to research (2), determining the exact prevalence of colonic inertia is difficult as most patients with severe constipation do not have transit studies performed to diagnose the issue.

Some studies have evaluated that the proportion of severely constipated patients suffering from colonic inertia (or slow transit constipation) varies between 15% and 37%(2).

This condition effects mostly women, and often begins at a young age, between 20 and 30(5).

In other words, if you have intractable constipation for which traditional approaches (diet, laxatives) have no effect, you should keep that condition on your list of possible causes of constipation until a diagnosis can confirm or refute this hypothesis.

How is colonic inertia diagnosed?

What it feels like

People who have colonic inertia generally do not complain of difficulty passing stools. Once the stools get to the rectum (the final section of the colon), the defecation reflex can be triggered. The issue lies in their inability to move the stools from the small intestine into the rectum, via the ascending colon, the transverse colon then the descending colon.

Let us look at a simple diagram to clarify this point.

If you have colonic inertia alone, the green parts are functioning properly, rectum included, where the defecation reflex is triggered by stretch receptors. But the pink parts (ascending, transverse and descending colon) may be effected by colonic inertia and may be lacking the electrical apparatus to convey the impulses responsible for forward movement.

You will have a feeling that your gut is constantly full, and that fecal matter is stuck and not moving, never making it to your rectum. Once it makes it to the rectum though, you can generally push it out.

Note: Just keep in mind that colonic inertia can also coexist with other conditions such as pelvic floor dysfunction, in which case evacuation from the rectum also becomes an issue. We will discuss this further down.

Medical Diagnosis

If you have intractable constipation, your doctor will likely run a battery of tests on you. For instance, if your transit is too slow, your doctor will want to check your thyroid hormones.

In a next step, your doctor may ask you to take a transit time measurement test. This test uses X-Rays to follow small markers that you have ingested through your gastrointestinal system. You will swallow special capsules for a few days, then an X-Ray snapshot will be taken on the last day to see where the different markers are.

Depending on the number of markers present in the different sections of the gut, this test can tell you how many hours your average transit time takes.

The average transit time in a normal person is 35 hours. This can go up to 72 hours and still be considered normal if no constipation symptoms are present. More than that though, with all other tests being normal, and you may be diagnosed with colonic inertia (slow transit constipation).

Coexistence with other conditions

Unfortunately, colonic inertia may not be your only problem. You may also havepelvic floor dysfunction, a condition we will discuss in a separate article. Pelvic floor dysfunction, also called pelvic floor dyssynergia or anismus, is a problem located in the rectum area, where the pelvic muscles cannot relax to let the stools be evacuated.

During the transit time measurement test mentioned previously, if some markers accumulate in the rectum without being evacuated successfully, dyssynergia may be present as well.

Colonic inertia may also be accompanied by small intestine and stomach motility and emptying issues, such as gastroparesis (the stomach is not emptying its content well and in a timely manner – you may feel full after a single bite). In other words, the “inertia” condition may not just impact the colon, it may also touch the upper portions of your digestive tract.

Treatment options

1. Nutrition

Before we start talking about nutrition, we need to take one step back and fully understand what colonic inertia does to digestion. If you have colonic inertia, a typical amount of food progressing through your digestive tract will fail to activate your colon’s contractile activity.

Let’s review one of the basic propulsion mechanisms in the digestive tract. A mass of food arrives at a particular location and stretches the walls of the intestinal mucosa. Stretch receptors, orchestrated by the enteric nervous system, send an electrical stimulus that triggers peristalsis, a wave-like forward propulsion of food. The net result is the mass of food being moved to the next section of your digestive tract.

If you have colonic inertia, there is an inherent defect in that electrical signaling pathway. The walls of the colon will be stretched, but certain areas of your colon will not respond. Nothing will move. The mass of food residues may end-up moving eventually, being pushed by the “upstream” mass of food being backed-up and accumulating. Or gravity may eventually pull things down. Too late though.

Fibers and other bulking agents
Based on the previous explanation, you can see how fibers, and bulky foods in general could be problematic. They add volume to your stools, which might get things moving if you are constipated and you do not have colonic inertia. But in this case, it will add insult to injury. Do not use them. And unfortunately for some, fruits and vegetables (not juiced, with fibers and skin) can also be very problematic.

I am a proponent of good fats for health. However, there is no clear picture regarding fats and colonic inertia. You will need to experiment and see how the ingestion of good fats effects your colonic inertia.

You already have lots of digestive trouble, bloating, maybe nausea. You may have lost a lot of weight due to a very restrictive diet. So the ability to ingest good fats is a big plus and will keep you healthy and fueled up.

Eat only the “good fats”. No hydrogenated fats (margarines, supermarket-prepared food, pastries like croissants, supermarket pie crust, etc).

If you can eat small amounts of meat, go for the pasture-raised type. Try full fat dairies from pasture raised cows or goats. Try eggs, with the yolk please, from local farms and happy hens.

I am not going to get into a long discussion on saturated fats here (not yet, maybe in a future article). If you take a look at all existing research, there seems to be no clear link between saturated fats and cardiovascular diseases. For more information, see this great analysis provided by Stephan Guyenet on his blog “The Whole Health Source”.

You may want to favor fatty foods that do not provide a lot of bulk and are easy to digest. An avocado added to a fruit smoothie for instance, with a couple of tablespoons of good oils such as fresh walnut (mechanically pressed and organic, keep in the fridge) or olive oil. A couple of soft-boiled eggs. Some almond butter made from peeled almonds (light colored, the skin with its fibers has been removed). Some fish oil (omega 3 fatty acids) to calm down potential inflammation in your gut.

Experiment slowly. Good fats are essential for your health. I do hope you can keep them fully integrated to your diet. If you tolerate them well, try to take olive oil first thing in the morning to see if it helps move food through your system.

Proteins are also critical for your health, they provide many essential amino-acids that are precursors to key neurotransmitters, and they help build and keep muscle mass.

But when you have colonic inertia, not all proteins are created equal. Beans contain proteins, but a lot of fibers too. Nuts, a nutritional powerhouse, can be problematic (especially with the skin). Meats can be hard to digest, especially if you also have gastroparesis.

Have you tried protein powders? Many reputable companies provide quality protein powders that you can blend in smoothies. Whey proteins can have a particularly beneficial impact to help you maintain your muscle mass.

Refined carbohydrates should be avoided. They are quickly transformed into sugars by our system, and trigger insulin spikes.

But for you, things are not so black and white. Refined carbohydrates (carbs without the fibers) may provide some quick energy without causing too much havoc, although they may also create a lot of gas and bloating, since certain bacteria feed on carbohydrates and generate gas as a byproduct of their digestion. See how you deal with mashed potatoes, or with rice pudding.

Overall, try to restrict those “empty calories” as much as possible. Do add a teaspoon of raw honey to your smoothie, or unprocessed molasses, or some good maple syrup, as those contain good nutrients and minerals.

The liquid diet
Which brings us to the liquid diet. I have made several reference to smoothies for a good reason. Many people with colonic inertia struggle with solid foods, but find solace in liquid food.

Liquid food is restricting, but it does not need to be boring. You can blend a lot of power nutrients into a variety of soups or smoothies.

Consider the following categories for smoothie ingredients:

  • Proteins: whey powder, whole fresh eggs, peeled almond or peanut butter, almond milk.
  • Good fats: egg yolk, butter, coconut milk or coconut oil, olive oil, avocados, fish oil, full fat organic yogurt from pasture raised cows or goats, etc.
  • Fruits and veggies: experiment with peeled peaches, red and dark berries, pears, kiwis, steamed or juiced carrots and broccoli, etc. Buy organic.
  • Some carbs: raw honey, unprocessed molasses, soaked oatmeal, cooked white rice, cooked spelt, etc. Go very easy on the grains.
  • Power foods: bee pollen, quality dark chocolate powder, green tea extract, ginseng extract, etc.
  • Other: since your nutrition is probably not optimal, you should consider adding a good quality multivitamin with minerals to your daily smoothie. The Life Extension Foundation has a powdered multivitamin mix, called "Life Extension Mix Powder" that I recommend.

2. Osmotic laxatives

Osmotic laxatives are worth a try. They draw water from your colon mucosa into the stools. They do not rely on the impaired nervous system of your colon, rather they work through fluid exchange.

Some people suffering from colonic inertia are finding constipation relief thanks to laxatives such as MiraLAX or other osmotic types. However they often have to take large quantities of them, getting to a point where the stools are very liquid and can move through without problems.

3. Biofeedback

Biofeedback uses special equipment to train the patient to relax her pelvic floor muscles. It is specifically used for pelvic floor dysfunction (also called dyssynergia).

However, it can be used if colonic inertia and dyssynergia are coexisting conditions. For those challenging cases, biofeedback will provide much needed relaxation of the pelvic floor musculature, although it won’t do anything for colonic inertia. Data points to a large proportion of dyssynergia patients seeing an improvement through biofeedback (more details will be provided on a separate dyssynergia page).

4. Surgery

If you have been struggling with colonic inertia for several years without getting any relief from nutrition, drugs or other therapies, your doctor may suggest surgery.

Surgery techniques have been found to be effective in certain types of colonic inertia patients.

Colectomy and Ileostomy
Colectomy involves the removal of a large portion of your colon, which is not performing its function properly. The exit of your small intestine is connected directly to your rectum.

Sometimes, the rectum and anus are also bypassed, bringing the end of the small intestine onto the surface of your abdomen, then attaching a pouch to it collecting fecal matter. This surgery is called ileostomy, and can be proposed when there is also concomitant pelvic floor dyssynergia. Your quality of life will be impacted by the constant carrying of the fecal pouch.

If you have both conditions, your doctor may suggest a colectomy followed by post-surgery biofeedback instead of an ileostomy. This latter combination will be less drastic, and you will not have to carry a pouch around.

Some studies(7)(8) show that a colectomy can have a high success rate (with a high percentage of satisfied patients, up to 80%). Note that post-operative fecal incontinence and diarrhea are sometimes observed.

Other studies show that the success rate is high only when colonic inertia is not accompanied with motility disorders of the upper gastrointestinal tract (as discussed previously, such as gastroparesis).

Therefore, careful consideration is necessary to figure out whether a colectomy will likely be effective for you. Your gastroenterologist will of course be your main counselor to reach that decision.

Both colectomy and ileostomy are not lightweight procedures. Therefore, going for one of those interventions is a serious decision. But only you can make it. Not your husband, not your son, nor your doctor. Those people are your support team. In the end, it is your carefully weighing of the pros and cons, and the eventual benefits on your quality of life that should be determinant.

Antegrade Colon Enema
For patients not willing to undertake subtotal colectomy or ileostomy, a minimally invasive procedure consists of opening up an access to the colon via a tube to perform antegrade enemas.

A traditional enema (with water inserted from the anus) is called a retrograde enema. Antegrade here means that the liquid is inserted at the beginning of the colon, via a tube inserted through surgery and providing an opening in the patient’s belly button or lower abdomen. The patient can then self-administer those antegrade enemas as necessary, on a daily basis or every other day, by pouring some liquid into the tube.

Some studies(6) show that antegrade colon enemas can bring improvements to a portion of slow transit constipation suffers, although the others need to undertake a colectomy in the long run. So the results are mixed, but since the surgery is fairly lightweight, it might be worth a try.


We have reached the end of a long article. If you have colonic inertia, you probably feel a bit overwhelmed by the amount of information give here. But information and knowledge provide the first step towards taking control of your health.

In this article, we have first defined colonic inertia, also called slow transit constipation, and explained that it can be accompanied by other conditions such as pelvic floor dyssynergia.

In terms of remedies, we have started with gentle approaches: nutrition and osmotic laxatives. Reorganizing your meals around more liquid foods, smoothies and soups, is challenging and takes some advance planning, but worth a try before you move to the surgery options.

In terms of surgery, we have evoked a lightweight intervention to enable antegrade colonic enemas. We have also presented the heavier approaches, colectomy and ileostomy, each with pros and cons to be discussed with your gastroenterology.

I hope this article has helped you. Whatever path you decide to undertake, I wish you good luck and trust that through your persistence, you will reach the end of the tunnel.


(1) He C-L, Burgart L, Wang L, et al. “Decreased interstitial cells of Cajal volume in patients with slow-transit constipation”. Gastroenterology 2000;118:14–2

(2) Frattini JC, Nogueras JJ. “Slow transit constipation: a review of a colonic functional disorder”. Clin Colon Rectal Surg 2008; 21: 146-52.

(3) Ordög T. “Interstitial cells of Cajal in diabetic gastroenteropathy”. Neurogastroenterol Motil. 2008 Jan;20(1):8-18. Review.

(4) Bassotti G, Villanacci V, Rostami Nejad M. "Chronic constipation: no more idiopathic, but a true neuropathological entity". Gastroenterology and Hepatology From Bed to Bench 2011, 4:109-115

(5) Ehrenpreis “Constipation, Colonic Inertia, and Colonic Marker Studies”. International Foundation for Functional Gastrointestinal Disorders. 2006.

(6) Rongen MJ, van der Hoop AG, Baeten CG. "Cecal access for antegrade colon enemas in medically refractory slow-transit constipation: a prospective study". Dis Colon Rectum. 2001 Nov;44(11):1644-9.

(7) Iannelli A, Piche T, Dainese R, Fabiani P, Tran A, Mouiel J, Gugenheim J. "Long-term results of subtotal colectomy with cecorectal anastomosis for isolated colonic inertia". World J Gastroenterol. 2007 May 14;13(18):2590-5.

(8) Sample C, Gupta R, Bamehriz F, Anvari M. "Laparoscopic subtotal colectomy for colonic inertia". J Gastrointest Surg. 2005 Jul-Aug;9(6):803-8.

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