This article was originally published in 2015 and has been updated in November 2018 to reflect the latest research.
Do you have gas, bloating, abdominal pain, and stool issues? Up to 20 percent of the U.S. population suffers from irritable bowel syndrome (IBS), a condition that adversely affects daily life. Instead of digging deeper to identify the underlying cause(s), conventional medicine typically offers medications to suppress gut symptoms. Read on to learn about five lesser-known causes of IBS that you may not be looking for.
Irritable bowel syndrome doesn’t have to be a lifelong sentence. Learn about five underlying causes of IBS you might not be looking for to help heal the gut from the inside out.
How Doctors Diagnose IBS
IBS is the most common functional gastrointestinal disorder. Yet it’s poorly understood—not only by those who suffer from it but also by many clinicians who try to treat it. (1) Symptoms of IBS include gas, bloating, and abdominal pain, accompanied predominantly by constipation, diarrhea, or both. Those afflicted report lower quality of life and activity levels and call in sick twice as often as the general population. (2) Depression and anxiety often accompany IBS, most likely through the gut–brain axis connection between the enteric nervous system of the GI tract and the central nervous system.
Over the years, diagnostic criteria have evolved, but IBS is now generally defined as recurrent abdominal pain at least three days per month in the previous three months, associated with two or more of the following: (3)
- Improvement with defecation
- Onset associated with change in stool frequency
- Onset associated with change in stool consistency
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IBS Medications Aim to Tame, Not to Treat
Not that long ago, IBS was dismissed as a psychosomatic disorder that was “all in your head.” Fortunately, it is now recognized as a legitimate gastrointestinal disorder, although it’s often poorly managed. Current treatments focus on alleviating the symptoms of IBS instead of actually fixing the underlying problems—but that’s a common theme in conventional treatment of modern chronic diseases. Medications prescribed for IBS include:
- Antidiarrheals
- Anticholinergic or antispasmodic drugs
- Laxatives
- SSRIs
- 5-HT3 antagonists
- Mast cell stabilizers (also used to treat asthma)
But those who use these IBS medications report low satisfaction, with little relief from the condition, and many of these drugs induce side effects that are similar to IBS symptoms themselves! (4, 5)
5 Causes of IBS You May Not Have Considered
In order to properly treat IBS, you’ll need to do some investigating to determine the cause. This article will summarize five causes of IBS that you may not be looking for—but should be.
1. Gut Dysbiosis
Ever-growing research links the gut microbiome to bone health, heart health, autoimmune disease, thyroid health, and more. It should be no surprise, then, that IBS is directly related to gut dysbiosis, a change in the composition of the gut bacteria. Up to 83 percent of IBS patients have abnormal fecal biomarkers, and up to 73 percent have intestinal dysbiosis. (6) Specifically, those with IBS tend to have decreased levels of “good” bacteria, such as Lactobacilli and Bifidobacteria, and increased levels of harmful strains such as E. coli and Clostridia. (7, 8) An increased ratio of Firmicutes-to-Bacteroidetes (two major classes of bacteria) is also common. (9)
Success in treating IBS with prebiotics and probiotics is further evidence that gut dysbiosis plays a role in IBS. A recent article reviewed 24 randomized placebo-controlled probiotic trials, the majority of which showed benefits of treatment. (10) Beneficial probiotic strains included B. animalis, L. rhamnosus GG, B. infantis, B. longum, and L. acidophilus. (11, 12, 13) Prebiotics, which act as food for the microbiota, can also help establish beneficial bacterial. (14, 15, 16)
Another strategy that can correct gut dysbiosis is a low-FODMAP diet, which eliminates foods containing certain carbohydrates that feed intestinal bacteria. (17, 18, 19) This method may help get the beneficial-to-harmful bacteria ratio back under control, but it works best as a short-term solution that is then followed by prebiotic/probiotic treatment. (20, 21, 22)
2. SIBO
Small intestinal bacterial overgrowth (SIBO) is a special subset of gut dysbiosis in which the small intestines harbor an abnormal number of bacteria. Compared to the colon, the small intestine should have a bacterial concentration that is considerably lower. Bacterial overload in the small intestine can interfere with digestion and nutrient absorption.
SIBO may be present in up to 80 percent of IBS patients, although a recent meta-analysis reported a huge range of estimates (between 4 and 78 percent) across 50 studies. (23) Part of the reason for the discrepancies is non-uniform IBS diagnosis, and the other part may be variations in SIBO diagnosis. I prefer the methane breath test over jejunal aspirate and culture, the conventional testing approach.
Antibiotics that are used to treat SIBO, like rifaximin, can also be effective for treating IBS, further evidence that SIBO may be underlying some cases of IBS. (24, 25) Or, SIBO may follow IBS incidence, especially if a person with IBS begins taking PPIs (acid-blocking medications) for indigestion. One of the many dangers of PPIs is the development of SIBO. (26, 27)
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3. Gut Permeability
The GI tract is lined with a single layer of tightly packed epithelial cells designed to keep pathogens and other unwanted species out of the bloodstream. If the barriers between cells become permeable, undigested protein molecules and bacterial toxins can pass through and trigger immune reactions and inflammation.
Leaky gut and associated low-grade immune activation affect between 12 and 50 percent of people suffering from IBS. (28, 29, 30) Low levels of E-cadherin, a protein involved in regulating gut permeability, have been reported in IBS sufferers who experience diarrhea and/or constipation. (31)
Supplements that can help reestablish the intestinal barrier include:
- L-glutamine
- MSM and quercetin
- N-acetyl glucosamine
- Mucin
- DGL slippery elm
- Marshmallow
- Chamomile
- Cat’s claw
GI-Revive contains several of these in an effective blend. Supplementing with probiotics can also help repair gut permeability. (33)
4. Gut Infection
Gut infections are another lesser-known cause of IBS. Many studies have confirmed a link between a single episode of bacterial gastroenteritis and future development of IBS. (34, 35, 36) Parasites such as B. hominis, Giardia spp., E. histolytica, Dientamoeba fragilis, and Trichinella spp. have also been correlated with progression of IBS, although causation has not yet been confirmed. (37, 38, 39)
Modern lifestyle has compromised the gut’s ability to resist infections from pathogenic bacteria and parasites. (High levels of stress, for instance, combined with factors such as the Standard American Diet, can easily lower our immunity.) Gut permeability, gut dysbiosis, and high stomach pH from chronic PPI use create more opportunities for pathogens to overwhelm or bypass the gut’s immune defenses.
5. Non-Celiac Gluten Sensitivity and Other Food Intolerances
The medical field once mocked non-celiac gluten sensitivity (NCGS), but the condition is slowly gaining acceptance even in conventional medicine. (40) Many of the symptoms—gas, bloating, abdominal pain, and changes in stool patterns—are indistinguishable from IBS, so NCGS can be difficult to identify. Brain fog and fatigue following gluten consumption are also very common.
In IBS patients, I see a number of other food intolerances, such as:
- Dairy
- Eggs
- Peanuts
- Seafood
- Yeast
- Soy
A large review of over 73 studies “confirmed that food allergy and intolerance should be considered as an underlying pathology for IBS.” (41) But bear in mind that food intolerances themselves are often symptoms of deeper causes like SIBO, gut infections, and/or gut permeability.
The cheapest tool to determine food intolerances is an elimination diet, which I outline in depth in my book The Paleo Cure.
What’s Your Experience with IBS?
IBS can be an unpredictable and even debilitating condition. Finding the root cause is not always an easy or quick road, but neither is a lifetime of symptom-suppressing medications with additional side effects.
In my practice, I have seen patients who have suffered from this condition for 20 years recover after we identify and address the underlying causes of IBS outlined above and fix their diets.
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I was diagnosed with IBS about 2 years ago. I was experiencing multiple (4-5) bowel movements a day- but not diarrhea and I had lower abdominal pain which sometimes radiated to the testicular area. The pain always worsens when I bend over (like putting on socks) and especially bending a lot while playing racquetball. Once I lie on my back (in a horizontal position) the abdominal pain immediately goes away. Even though I have multiple bowel movements/day it often felt like I was constipated. My stools consistency varied from flat/ribbonlike to small pebbles to more normal large stools. I have also routinely experienced the inability to expel gas which seems to cause more abdominal pain. After getting colonoscopies, contrast enterography, capsule endoscopy, the doctor put me on Rifaximin in case I had SIBO. The Rifaximin didn’t do anything.
Now I am taking IBGard which has seemed to allow me to pass gas more frequently and has also eliminated the feeling of constipation. I still have multiple bowel movements/day but never diarrhea.
The fact that lying down on my back immediately relieves my abdominal pain makes me think that either trapped gas in my abdomen is causing the pain or there is a nerve that is being impinged upon- especially when I bend over. No one can figure out why bending over exacerbates the abdominal pain.
I’ve had chronic diarrhea since the end of April. Within the last month or so I began taking a tbls. or so of psyllium seed/day and the diarrhea subsided. Thank heavens there were only a few days that I had problems all day long. It was usually first thing in the morning or once in the evening, if I had a glass of wine, etc. I had an erratic schedule a few days ago and didn’t take the psyllium seed and it came back with a vengeance. With the psyllium seed, the diarrhea is under control, but my stools look very strange and vary from day to day. I have been on a Weston Price type diet for the last 3 years or so. The day before I got ill, I ate a lot of raw cabbage at a restaurant. Other than that, I can’t see that this is related to anything I’m eating. I’ve wondered if I have a parasite and have tried taking diatomaceous earth to rid myself of parasites. I haven’t been to the doctor mainly because unlike many others, I’m not in pain, I don’t feel that my health is suffering and the majority of the time it’s only a problem first thing in the morning. Still, it’s become a chronic issue which is not normal. If anyone knows of a good doc in Georgia or has any advice, I’d love to hear it.
Thanks
From a newsletter” Researchers looked at a group of 80 postmenopausal women. All of the women had a confirmed IBS diagnosis. For those who don’t know about IBS, it is an uncomfortable and distressing condition in which patients’ bowel functions alternate between constipation and diarrhea. But did you know that IBS comes in two flavors? One type of IBS is the constipation predominant type or IBS-C. The other type is the diarrhea predominant type or IBS-D. Here’s what the researchers did.
Before the experiment started and during the study, they checked the patients’ 6-sulfatoxymelatonin (6-HMS) concentration in their urine. The 6-HMS is a marker of melatonin. The higher it is in the urine, the more melatonin the body is making. They gave all of the women either melatonin supplements of 5 mg at bedtime along with 3 mg on an empty stomach during the day or placebo pills. Then for the next six months, they measured the amount of symptoms the patients were having. These included pain, bloating, diarrhea, constipation, etc. Here’s what they found.The women who had IBS-C responded very well to the melatonin supplements compared to the placebo. Their levels of abdominal pain and bloating decreased a remarkable 70%. And their constipation improved 50%. And the researchers discovered that the higher their levels of 6-HMS, the better they responded to the melatonin. This is strong evidence that the effects of the melatonin worked better in women who were already deficient, had nothing to do with placebo action, and were dose dependent.
What about the IBS-D group? Surprisingly, they showed no benefit at all. So it seems that IBS-C is caused to a large extent by a melatonin deficiency, whereas the IBS-D has other causes. In the words of the researchers, “Melatonin can be used as part of the treatment of IBS, particularly in patients with constipation-predominant IBS.” But why did the melatonin work at all?
Melatonin is thought by many to be a brain hormone. But the fact is that more melatonin is produced in the intestines than in the brain. And one of the primary actions of melatonin in the intestines is to relax the smooth muscles that surround them. This, of course, is important when it comes to symptoms such as intestinal pain and bloating. Don’t forget that melatonin starts becoming deficient in most people in their 20s. By the time we hit our 50s, the amount of melatonin our bodies make can be extremely low. This is why so many people have bowel issues and constipation as they get older. A little melatonin in many cases will take care of these problems. And one more thing.
Why didn’t the people taking the melatonin during the day get sleepy from it? It’s because melatonin is not the same as a sleeping aid. Of course, it’s important for sleep. But our bodies make it all day long for many other functions. So if you have IBS, especially if it’s the IBS-C version, the odds are good that your body is crying out for some melatonin. And remember that the symptom relief was dose dependent. So if a little doesn’t work, try some more. Melatonin is extremely safe, and unlike other hormones, taking high doses of melatonin does not cause the body to make less. I routinely give 20-60 mg of melatonin to my patients. And I take 20 mg every day.”
I have been wanting to try kefir for my IBS but because I am very intolerant to casein in milk, I have not been able to. Is there something else that would provide a benefit similar to that of kefir that is not made from milk?
For me, my IBS (c) was caused by too much fat and not enough soluble and non soluble fibre. It took years of suffering before figuring it out but once I did the results were overnight relief. Helpforibs.com is a good site.
Does Chriskresser know that they can also be caused by trigger points in the stomach? Pretty weird that he claims to be an expert about chronic pain and yet he never even mentioned trigger points once on this website..
I had IBS (self-diagnosed) from 1980 to 2000. It started suddenly one night during midnight mass in a very crowded church. We had wine & cheese before leaving for church, haha, bad idea! I had to keep getting up and waiting in line for the single toilet and my family was ticked off at me. Had really bad diarrhea and gas like jet-propulsion off the toilet. I can laugh about it now but it was the beginning of 20 years of agony. I grew out of it or something….
I was mis-diagnosed with IBS for two years – a month ago a tummy scan revealed i have a 10cm tumour on my ovary! Ladies ask for tummy scans please!
Each person is different. Each med, each food item, will cause different reactions in different people. I have treated migraines and IBS through the process of trial and error over the last 10 years. Results for me: white rice does not work for my gut. White potatoes do work. Red meat causes migraine, whereas chicken & fish don’t. Like that, I am now down to what works pretty well. No one practitioner has helped me exclusively. Many have contributed to my finding my way. No one can do it for you.
What about using Prescript Assist??
Can this Soil based Probiotic help to fight IBS – D??
Lyme disease is a big time cause in IBS and leaky gut. It should be on this list!
I was diagnosed with IBS 2 years ago, given Buscopan to take as I needed and told to learn how to deal with it. The med did give me some relief at times but I also started breaking out in hives which then progressed to angiodema. An immunologist diagnosed me with Chronic Idiopathic Urticaria and offered to prescribe me with super strong anti-histamine meds which I declined as I felt that all this was doing was dealing with the symptoms. I have gradually removed milk, eggs, grains, nuts, refined sugar and soy from my diet and added Prescript- Assist and fermented foods. With recommendation from my functional medicine Dr I take 1Tbs flax, 1Tbs hemp seeds + 1Tbs Chia seeds every morning soaked in hot water/coconut milk and 60billion Bifidobacterium lactis every day (to help restore the bacteria levels in my colon) The IBS symptoms are waaaay better, I am no longer constipated, just get occasional gas and bloating. The CIU symptoms are getting better….just not where I want them to be….yet 🙂
Chris, no one likes to talk about this, but ovarian cancer presents with these symptoms and is often dismissed as a possibility. Consequently ovarian cancer is dxed late. This os ovarian cancer awareness month, so how about spme awareness here. BTW I was treated for a diarrhea style of ibs in early 2000s. breath test, 2 courses xifaxin –cured. Ovarian cancer for me presented as constipation different from anything i had ever experienced. GI doc referred to earlier IBS dx and decided on pelvic floor syndrome. Was he wrong! So be sure to exclude the unpleasant to think about..It is much better when caught early.
I have had IBS-C for most of my 62 years of life and have found that my situation responds best to regular strenuous exercise, fiber, plenty of fruits and veggies, and stress reduction.
My 9yo daughter suffers from IBS-C which started when I stopped breastfeeding but got intermittently worse throughout the years and exploded into severe pain about a year ago. We are on permanent Miralax and milk of magnesia, now we are trying these drops in water… we’ve tried low fodmap diets and a ton of other things. Poor girl. We are still trying to find a solution.
That’s rough. Where are you located? I think I could help. I am in the Boston area.
I am in the Boston area and would like to know the name of the dr you recommend !
thanks !
Be advised that the FDA is studying whether or not ethylene glycol has negative health risks associated with its use. Also, it is NOT intended for use for more than 7 days. I had severe nervous system effects which caused extreme panic and anxiety for over an hour after taking a product with ethylene glycol in it. Therefore, IMHO, I feel as if this ingredient can cause severe nervous system damage just like an article I read some time ago alluded to. Have you tried some natural fiber products? Anything but this controversial Miralax would be better. Good luck. P.S. If the FDA is concerned, I am too… as they rarely act in the public’s best interest in spite of what one might think.
Make sure she is on a probiotic. Some work better for constipation than others.
Try Megadophilous, which you can find in a vitamin store.
Also, perhaps artichoke capsules and/or milk thistle to get the bile going.
Good luck, I hope she feels better
I just interviewed specialist Gastroenterology Dietician Julie Thompson today and she went into a full detailed list of probiotics, with science based research attached to it, for IBS-D, IBS-C, IBS-A, Bloating, spasms and lots lots more. You can learn more here..http://fuelyourselffabulous.tv/live-show/
I also experienced nervous system damage using Miralax. My doctor told me it is harmless as it is supposed to stay in your gut but I think if you have any gut damage/inflammation/leaky gut then it will get into your blood stream and cause problems. When I realized it was the Miralax causing my worse health issues I googled it and found there are a number of lawsuits against the company as many people have found it to be toxic and in a few cases there have been deaths. I don’t mean to scare you but just want you to know that this may not be good for your daughter and there are alternatives. Things I found helpful for constipation are Renew Life CleanseMore capsules, this is the most gentle herbal laxitive I have found and I have tried many. I recently stopped using this and instead now use a high dose of magnesium bisglycinate by Naka PRO MG12. To find the correct dose for my body (and as advised by a dietician) I took the magnesium through the day until I reached bowel tolerance at 1800mg then cut back and maintained a dose of 1400mg. Slowly I was able to cut down my dose to 600-800mg per night. I also take lots of vitamin C. My bowel movements are now normal, regular, pain free and healthy after 20 years of IBS.
Another aspect of gut inflammation that is not so well know is histamine intolerance, for more information google the ‘low histamine chef symptoms’ to see if your daughter may have this. If she does this website will be helpful but also look up the histamine food lists as avoiding or cutting back on the huge array of high histamine foods can really help with symptoms. Good luck, I hope your daughter gets better.
I recommend using vitamin c flush for getting her symptom free, then find root cause and address it. Research vitamin c and you will find it to be a god send, you will find some saying it lacks effects and or have side effects. The real experts on vitamin c will tell different, it’s one of the cheapest, safest and most effective substance known.
Good luck!
Can you please recommend a reputable online resource for finding a well-trained and experienced functional medicine practitioner in my local area?
To look for an appropriately trained practitioner, here are two options:
http://www.naturopathic.org/AF_MemberDirectory.asp?version=2
https://www.functionalmedicine.org/practitioner_search.aspx?id=117
Good luck!
Beth, I’m not local but I use functional medicine around the world. With much fairer prices than most without sacrificing experience or knowledge. I give 15 minute free consults on my site to hear what’s going on and see how I can help.
After abdominal surgery, how do I buil up the right gut flora? I am eating for the first time after 6 days of having an asleep system?
I want to eat healthy and take pro-biotics… But how?
Gut health is so important and the first physical thing I assess with clients’s health. Thanks for an awesome article.
I was diagnosed with IBS by my primary care last March. I had been experiencing chronic constipation for two years, thinking at first that it was all in my head, that I was just experiencing anxiety over food again (relevance: 7 years ago I was hospitalized for anorexia). But FINALLY I went to the doctor who agreed that the constipation and extreme bloating I was experiencing was not normal. She suggested following and anti-inflammatory diet and recommended the book by Jennifer Black “The Anti-Inflammation Diet and Recipe Book”. I’m a very healthy eater so all I had to do was cut out wheat/gluten and dairy. My symptoms were completely resolved in about a month and my BMs started to regulate. When I added wheat/gluten and dairy back in, each for a week at a time, I felt horrible!!! I have noticed an improvement in my energy levels, concentration, hemorrhoids and obviously my GI functioning. When I went back in to my doctor after the first month, she said that I even LOOKED less bloated!! For the most part I strictly adhere to the anti-inflam diet. Every once in a while I’ll allow one meal or treat out with friends/on special occasions where I indulged in an irritating dessert or something. But not without discomfort!! I swear by the anti-inflam, and after my master’s in nutrition want to learn more about functional and nutritional medicine!!
I was diagnosed with IBS over 20 years ago and it waxed and waned. Over the past two years, I started having all kinds of issues that my acupuncturist recognized as problems with the stomach, liver, and spleen meridians. I would get some relief from acupuncture and then would go back to presenting problems (as evidenced by the changes in tongue color). I picked up Chris’ book from the bargain table at the bookstore and thumbed through it, thinking it was worth a try. Then I looked into specific IBS diets, and found the low FODMAP approach. I employed a 30 day elimination diet and ALL of my symptoms disappeared.
Now my diet is PALEO-based with modest amounts of cane sugar, honey, and dairy. I can also have small amounts of wheat and wheat like-grains (einkorn, spelt), but I CANNOT eat anything with corn and not really any rice. I consume very little onion and garlic as those definitely causes issues as does broccoli and other non-fermented cruciferous vegetables. Same for fruits–berries and citrus are fine; apples in reasonable amounts, but very little in the way of stone fruits.
It means limited meals outside the house and can make vacations a bit challenging, but my symptoms have disappeared, my skin cleared up, and I have lost weight without trying.