Irritable Bowel Syndrome as it Relates to FODMAPs, Gluten, Stress, and Rifaximin

Are you tired of experiencing gastrointestinal pain, bloating, and cramping? Do suffer with constipation, diarrhea, or both? If so, you may have irritable bowel syndrome, also known as IBS.

IBS is a common condition in our society, with 45 million Americans estimated to have this condition (1). Most IBS sufferers associate their symptoms to be worse after consuming certain foods. However, food reactions can vary from patient to patient, and it can be difficult for an IBS sufferer to ascertain each and every food that is problematic. Living with IBS can be difficult as the gastrointestinal pain and bloating can occur unexpectedly, making social situations such as dinner parties potentially less enjoyable. Thankfully, the gastroenterology community has conducted extensive research on IBS so that new therapies could emerge for this unpleasant syndrome.

A few years ago, researchers out of Australia highlighted the importance of a group of foods, termed FODMAPs, for IBS patients. The abbreviation “FODMAP” stands for fermentable oligo, di, and monosaccarides as well as polyols. In essence, these are forms of carbohydrates that are in certain foods which can attract water into the intestines or result in excessive production of gasses such as hydrogen, therefore resulting in symptoms of pain, bloating, cramping, diarrhea, constipation, or diarrhea alternating with constipation. Many foods containing high amounts of FODMAPs are seemingly healthy, and include foods such as broccoli, apples, pears, mangos, milk, whole wheat, artichokes, asparagus, broccoli, cauliflower, onions, garlic, and beans to name a few (2). The full list is more exhaustive, but also know that there is not a universal agreement on what foods are high in FODMAPs, such that lists can vary subtly from source to source.

Even though there is some ambiguity regarding high FODMAP foods, the literature is definitive that FODMAPs pose a problem for IBS patients due to the fact that when they are consumed water is attracted into the intestines or the bowel, and the bacteria in these areas of our digestive tract also produce excessive gas in the presence of these carbohydrates. Therefore, elimination of these foods can be helpful for those with IBS due to their being less fluid and gas in the gastrointestinal tract (3). Commonly, patients are recommended to remove FODMAPs for 6 weeks, and then to introduce each food, such as an apple, back into the diet one at a time and then to observe if there is a worsening of symptoms.

In our experience, many IBS patients become confused at the point of introducing high FODMAP foods. The reason for this is that many IBS sufferers will have reactions to several foods, leaving them depressed that their diet is so limited and also confused as to which FODMAP foods pose the greatest problem to their IBS. This highlights that there are other issues occurring in IBS patients than simply problems with FODMAPs. These include dysbiosis, small intestinal bacterial overgrowth, Leaky Gut Syndrome, and stress to name a few.

Within the intestines and colon there are populations of bacteria and other organisms termed the “normal flora.” Likely you have seen commercials advertising probiotics and the benefits of using these to improve gastrointestinal health. IBS sufferers have been found to have different populations of bacteria within their intestines when compared to people without IBS. This is termed dysbiosis. Therefore, when a patient with IBS removes FODMAPs from the diet, the abnormal populations of bacteria are starved of the foods they prefer to eat. However, when FODMAPs are introduced, the symptoms of IBS often return because these abnormal bacterial populations still reside in the intestines waiting to digest their favorite carbohydrates from the FODMAP list (4).

Not only can IBS patients have the wrong types of bacteria in their intestines, but they can also have too many bacteria as well. This is now termed small intestinal bacterial overgrowth, referred to as SIBO. SIBO is diagnosed by drinking a carbohydrate solution, either glucose or lactulose, and then measuring the amount of hydrogen or methane expelled back up out of the intestines to the mouth. SIBO can be associated with both diarrhea and constipation forms of IBS, and there is now some discussion that when methane is produced there is a greater probability of an individual having constipation versus diarrhea. SIBO is thought to occur in 31% of IBS sufferers and upwards of 45% of those with IBS who have diarrhea (5). The fascinating part about SIBO is that there is an antibiotic, which is gaining acceptance in the treatment of this condition.

The antibiotic is termed Rifaximin. Unlike most antibiotics, which will absorb into the blood stream so that infections in the sinuses or the lungs can be killed, Rifaximin is locally acting and resides in the gastrointestinal tract. We like to think of it as a bulldozer killing off the bacterial overgrowth seen with SIBO. Rifaximin has been shown to not only help with SIBO, but also it improves dysbiosis, such that those populations of “abnormal or bad bacteria” become removed allowing good bacteria to flourish (6,7). In our clinical experience, we have seen several patients placed on Rifaximin with good results, but we have also seen those who have good results for some period of time only to have their symptoms ultimately return. This quite possibly occurred due to them eating a poor diet that in essence grew back the abnormal populations of bacteria responsible for their IBS. Even more interesting, is that research has emerged demonstrating natural herbal remedies to be as effective as Rifaximin in treating SIBO (8). Furthermore, studies have demonstrated Rifaxmin to improve the integrity of the barrier separating the food within the intestines from the blood supply where the food is absorbed (7).

This barrier for all intents and purposes is one cell layer thick, and the cells of the intestines are bound together by proteins termed zonulin and occludin. We like to think of these proteins as being akin to cables holding blocks together. The zonulin and occludin proteins holding the intestinal epithelial cells together is referred to as a “tight junction.” Studies are now emerging that demonstrate this barrier to be compromised in IBS patients, and the current line of thinking is that the zonulin and occludin proteins break down at an excessively high rate, food molecules or pieces of bacteria as a consequence are absorbed, resulting in activation of the immune system. This process is termed Leaky Gut syndrome or intestinal hyperpermeability. We prefer the latter term, though the term Leaky Gut syndrome has gained greater acceptance and recognition. Please keep in mind that this is a newly acknowledged entity in the literature, and that your doctor may have not heard of this before as its validity has only been substantiated for several conditions in the last couple of years.

This is where the infamous gluten enters the discussion. Many patients with IBS have reported to their doctors that they felt better being on a gluten free diet. Doctors scratched their heads due to the fact that these IBS patients did not have Celiac disease. Celiac disease is an autoimmune condition where the immune system will attack the gastrointestinal tract when gluten is consumed from the diet. Foods high in gluten include wheat, barley, oats, and rye. More simply, gluten rich foods include beer, breads, cereals, pasta, and pizza. The foods most of us enjoy eating.

To summarize this discussion on IBS and gluten, early studies demonstrated gluten to be an issue for these IBS sufferers, and repeat studies demonstrated that IBS patients reacted to FODMAPs, felt better off of FODMAP foods, and then would react to gluten and dairy molecules when these foods were introduced in a double blind placebo controlled trial. The travesty is that many mainstream media resources reported that gluten is not the cause of IBS. Though it is not the only cause, it is one of the associated causes for many IBS sufferers (9).

Further research demonstrated that IBS patients do not feel well mentally when eating gluten. In fact, the researchers discovered that gluten consumption most specifically resulted in depression. Unfortunately, you likely have not heard about this in the media. It is very interesting that gluten in these individuals is resulting in a symptom far removed from the gastrointestinal tract (10).

For those who are gluten intolerant but do not have Celiac disease (termed Non Celiac Gluten Sensitivity), gluten has been found to actually cause Leaky Gut syndrome. Though it does not create the Celiac disease reaction, it does cause Leaky Gut syndrome to the same degree as that observed in Celiac disease patients (11). Therefore, gluten is not the only cause of IBS, but the research demonstrates that it can have an effect for the IBS sufferer not only from a gastrointestinal perspective but also in terms of it being associated with depression in these patients.

Stress can also be a critical for IBS patients. The intestines for those with IBS also have neurological changes as compared to healthy controls. Stress in an IBS sufferer will result in the intestines becoming hypersensitive to food moving through the gastrointestinal tract. This natural movement of food through the intestines and colon is referred to as peristalsis. The medical approach for treating this stress and anxiety based reaction in IBS sufferers is to use antidepressant medications, which have been shown to decrease this sensitivity of the intestines this movement of food.

The alternative and holistic approach is to look at what factors are perpetuating stress in an individual’s daily life, and to work with them on stress management strategies. We have found that some IBS patients have such overwhelming stress that they will not improve until a psychologist or psychiatrist is consulted and the underlying cause of the problem be dealt with. Other IBS patients in our experience respond to neuroplasticity-based exercises, which are in essence brain-training exercises that can help to calm down stress based responses in the body.

Yes, probiotics can help those with IBS. However, hopefully by now you appreciate that the causal mechanisms behind IBS are rather complicated, and though probiotics may offer some relief, again in our opinion they are not the ultimate answer.

At this point, you as the IBS sufferer should have a more solid understanding as to what factors are causing your symptoms, and what other factors that may be destabilizing your condition and not allowing you to feel better in the long run. It is important for those with IBS symptoms to be evaluated by a doctor and gastroenterologist if necessary, as other more ominous conditions can mimic IBS. With that being said, the literature is now supporting an interdisciplinary approach for the management of IBS as teasing out the nuances of this condition can be difficult for a patient attempting to do so on their own.


  1. Shepherd SJ, et al. The role of FODMAPs in irritable bowel syndrome. Curr Opin Clin Nutr Metab Care. 2014 Nov;17(6):605-9. doi: 10.1097/MCO.0000000000000116.
    2. van der Waaij LA1, Stevens J.[The low FODMAP diet as a therapy for irritable bowel syndrome]. Ned Tijdschr Geneeskd. 2014;158:A7407.
    3. Ong DK1, et al.Manipulation of dietary short chain carbohydrates alters the pattern of gas production and genesis of symptoms in irritable bowel syndrome. J Gastroenterol Hepatol. 2010 Aug;25(8):1366-73. doi: 10.1111/j.1440-1746.2010.06370.x.
    4. Schmulson M1, et al. Microbiota, gastrointestinal infections, low-grade inflammation, and antibiotic therapy in irritable bowel syndrome: an evidence-based review.Rev Gastroenterol Mex. 2014 Apr-Jun;79(2):96-134. doi: 10.1016/j.rgmx.2014.01.004. Epub 2014 May 23.
    5. Moraru IG, et al. Small intestinal bacterial overgrowth is associated to symptoms in irritable bowel syndrome. Evidence from a multicentre study in Romania.Rom J Intern Med. 2014;52(3):143-50.
    6. Saadi M1, McCallum RW.Rifaximin in irritable bowel syndrome: rationale, evidence and clinical use.Ther Adv Chronic Dis. 2013 Mar;4(2):71-5. doi: 10.1177/2040622312472008.
    7. Gao J1, Gillilland MG 3rd1, Owyang C1. Rifaximin, gut microbes and mucosal inflammation: unraveling a complex relationship.Gut Microbes. 2014 Jul 1;5(4):571-5. doi: 10.4161/gmic.32130.
    8. Chedid V1, et al. Herbal therapy is equivalent to rifaximin for the treatment of small intestinal bacterial overgrowth.Glob Adv Health Med. 2014 May;3(3):16-24. doi: 10.7453/gahmj.2014.019.
    9. Biesiekierski JR1, Peters SL, Newnham ED, Rosella O, Muir JG, Gibson PR. No effects of gluten in patients with self-reported non-celiac gluten sensitivity after dietary reduction of fermentable, poorly absorbed, short-chain carbohydrates.Gastroenterology. 2013 Aug;145(2):320-8.e1-3. doi: 10.1053/j.gastro.2013.04.051. Epub 2013 May 4.
    10. Peters SL1, Biesiekierski JR, Yelland GW, Muir JG, Gibson PR.Randomised clinical trial: gluten may cause depression in subjects with non-coeliac gluten sensitivity – an exploratory clinical study.Aliment Pharmacol Ther. 2014 May;39(10):1104-12. doi: 10.1111/apt.12730. Epub 2014 Apr 1.
    11. Hollon J1, Puppa EL2, Greenwald B3, Goldberg E4, Guerrerio A5, Fasano A6. Effect of gliadin on permeability of intestinal biopsy explants from celiac disease patients and patients with non-celiac gluten sensitivity.Nutrients. 2015 Feb 27;7(3):1565-76. doi: 10.3390/nu7031565.


  1. How can I get a copy of your book Power Health Back to Basics? Can I order this book from you?

    Thanks so much,

    Judy Ann Mirman

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