There is a strategy that has recently become more popular; it is a dietary approach that I have seen work well for many of my patients, and that evidence is growing in support of. Known as the Low FODMAP Diet, this method has been demonstrated to reduce functional gut disorder symptoms in approximately 75% of patients. (2) Understanding how FODMAPs affect the gut and knowing how to eliminate them from your diet may be the key to getting your IBS symptoms under control.

What are FODMAPs?

The acronym FODMAP stands for Fermentable Oligosaccharides, Disaccharides, Monosaccharides And Polyols. These short-chain carbohydrates are incompletely absorbed in the gastrointestinal tract and can be easily fermented by gut bacteria. (3) These sugars also exert an osmotic effect, increasing fluid movement into the large bowel. (4) The fermentation and osmosis caused by these undigested sugars are a cause of major IBS symptoms such as gas, pain, and diarrhea.

There are many common foods that are high in FODMAPs that can potentially contribute to IBS symptoms, even if they are considered healthy by most standards. Lactose from dairy products, fructose from certain fruit, coconut products, and sweeteners, fructans from fibrous vegetables, and polyols from fruit and sugar alcohols are all rich in FODMAPs and can be difficult to digest for people with functional gut disorders. These foods can cause serious and painful symptoms in those with IBS and Crohn’s disease.

Who may have FODMAP intolerance?

While most IBS patients are FODMAP intolerant, consuming FODMAPs does not actually cause IBS; it simply exacerbates symptoms. (5) Therefore, while many people may be able to consume a large quantity of FODMAPs with no problem, some people will experience an abnormal or exaggerated response to the presence of these poorly absorbed saccharides. (6) And while all FODMAPs can potentially factor in the development of IBS symptoms, the relative contribution of different types of FODMAPs varies across ethnic and dietary groups depending on the amount of each in the diet. (7) Additionally, individuals differ in their amount of malabsorption of FODMAPs such as fructose, lactose, and fructans, and therefore are more or less sensitive to certain FODMAPs in particular.

So what causes FODMAP intolerance? There are a few possible explanations that have been explored in clinical study. In some cases, small intestinal bacterial overgrowth, also known as SIBO, contributes to the development of IBS symptoms and FODMAP intolerance. (8) The presence of pathogenic bacteria in the small intestine causes excessive fermentation of these carbohydrates, increasing gas production and allowing for the proliferation of uncontrolled gut bacteria. In other cases, certain individuals may lack adequate enzymes to break down and absorb the fermentable sugars before they reach the colon, contributing to the osmolarity changes and bacterial fermentation that occurs in the large intestine.

Of course, emotional and physical stress are also known to be contributing factors to the development of IBS, and could induce FODMAP intolerance for reasons not yet fully understood. (9) In these cases, disturbance of gut microbiota is a likely causative factor; as we know, stress alters the gut flora significantly and could be the reason why stress, FODMAP intolerance, and IBS are so closely linked.

How can you treat FODMAP intolerance?

First, addressing intestinal bacterial overgrowth or imbalance is key; even if you don’t have IBS, gut dysbiosis can lead to poor digestive function as well as contributing to FODMAP intolerance. There are a few gut-healing protocols available today, such as the GAPS Diet or the Specific Carbohydrate Diet; my personal approach is similar to an autoimmune Paleo diet. I often recommend probiotics to my patients to help balance out their gut flora, and occasionally recommend antimicrobial treatments depending on the severity of the individual gut infection. Managing gut flora is a highly individual process, so it’s important to pay attention to your own symptoms when coming up with a treatment plan.

In addition to addressing gut bacteria, following a low FODMAP diet seems to be the most effective dietary intervention to help reduce chronic IBS symptoms. (10) Many clinical trials have shown a high level of success from IBS patients who reduce or eliminate FODMAP containing foods from their diet. (11, 12, 13) In addition, avoiding gluten may help reduce IBS symptoms further, according to some research. (14)

While a “Paleo” or “Primal” diet may eliminate many of these culprits, there are a few Paleo-friendly staples that can worsen FODMAP intolerance symptoms. I’ve written about coconut milk causing digestive distress in some individuals, and coconut milk is an unfortunately high source of FODMAPs. Many fruits such as apples, peaches, mangoes, and watermelon are FODMAP rich, and dried fruits are especially problematic for those with intolerances. Even certain vegetables that are normally quite healthy can be problematic for those suffering from IBS; asparagus, brussels sprouts, broccoli, garlic, and onions are just a few of the vegetables that could be exacerbating symptoms.

To determine which specific foods that may be causing your IBS symptoms, I recommend reviewing this basic but informative chart featuring different types of FODMAPs and the foods they are found in. You may be consuming a FODMAP-rich food without knowing it, and reducing or eliminating consumption of these foods may help alleviate IBS symptoms. This chart also provides a list of low FODMAP foods that can be enjoyed in place of these problematic foods.

For much more information about FODMAP intolerance, as well as an extensive list of FODMAP foods and an in-depth gut healing protocol, check out my Personal Paleo Code. In this detailed guide, I explain how to best adapt the standard Paleo diet into one that can help relieve IBS symptoms without needing to restrict your diet indefinitely. It’s a protocol I use with my patients, and many have found success without drugs or surgical intervention. It’s certainly worth a try for anyone suffering from chronic digestive disorders.