• IBS Diet

    IBS/SIBO Diet



    Food is a major trigger of digestive symptoms, and you have no doubt noticed your symptoms worsen after a meal or eating certain foods. You may have pin-pointed a few foods that cause issues, but the rest usually remain a mystery.

    There is so much information out there about what you should and shouldn’t be eating that it can become very confusing to know what’s right for you.

    I find this to be a huge source of frustration for our clients, so  have devised an eating plan based on a framework of safe foods. These are foods known to cause the least reaction and reduce symptoms.

    The IBS Diet draws on the science and wisdom of a number of therapeutics diets, including:

    • Low FODMAP Diet
    • SIBO Bi-Phasic Diet
    • Specific Carbohydrate Diet
    • Fast Tract Diet

    Fermentable Carbohydrates


    We know there is a connection between food and the symptoms of IBS, but what researchers are discovering is that food alone isn’t the cause of the symptoms, rather when the environment of the gut is altered, by dysbiosis, SIBO, parasites, etc., symptoms may be exacerbated by certain components in the food

    There is strong evidence that certain foods can contribute to the symptoms of IBS through the effects of malabsorption of carbohydrates. (3, 4) (Malabsorption is a failure to fully absorb nutrients from the gastrointestinal tract.)

    Most of the food we eat is broken down into smaller parts and absorbed in the small intestine. However, our bodies don’t produce the enzymes needed to break down most complex carbohydrates, so our gut flora provides the enzymes needed for this.

    As undigested food passes through the large intestine, the bacteria ferment it. This process produces short chain fatty acids, and results in the production of gases including hydrogen and methane.

    The reaction that IBS patients get from eating certain foods has been attributed to their inability to fully absorb particular types of carbohydrates. Once they arrive in the lower small intestine and colon, these poorly absorbed carbohydrates provide the food for bacterial fermentation, which then leads to the gas, bloating, pain and general abdominal discomfort. (5)

    Because some of these carbohydrates are in very small particles, when they are not fully absorbed they can affect the gut osmotically, causing more water to be delivered to the bowel. In some people, this leads to episodes of diarrhea.

    In other people who have an overgrowth of bacteria in the small intestine (SIBO), when bacteria is fermenting certain types of carbohydrates in their small intestine, the gas being produced will bloat a very narrow section of the bowel, which causes abdominal distension, discomfort, bloating and pain.



    Research has been accumulating that shows that IBS patients can be helped by excluding a group of food components from their diet known as FODMAPs. Evidence has emerged that FODMAPs can play a role in causing the symptoms of IBS. (6)

    The term FODMAP is an acronym, which stands for Fermentable, Oligo-, Di-, Mono-saccharides and Polyols. These are short chain carbohydrates that are poorly absorbed in the small intestine.

    One study found the restriction of dietary FODMAPs to be beneficial in reducing the symptoms of IBS in at least 74% of patients with IBS. (7)

    In another study, researchers found:

    “Restricting the intake of foods high in FODMAPs reduces the amount of colonic fermentation, gas production, and small intestinal fluid volume. Dietary therapy can, therefore, be directed toward reducing such gut distension by limiting both gas production and the osmotic effect.” (8)

    Since bacteria use carbohydrates as their energy source and ferment them into gas, we have found a lower fermentable carbohydrate diet can directly reduce symptoms by decreasing the amount of gas produced. A reduction in fermentable carbohydrates forms the first phase of our eating plan.

    Why extra fibre may not be helpful


    For most people with IBS, especially those with constipation, one of the first recommendations they hear is to increase the fibre in their diet or to take fibre supplements. However, research and the experience of many patients show mixed results, and in some cases a worsening of symptoms.

    For healthy people, the fermentation of fibre in the large intestine is considered healthy. Unfortunately, for people with digestive problems, consuming too much fibre may cause excess fermentation.

    Research done at Addenbrooke’s Hospital NHS Trust, Cambridge, UK linked fibre with abnormal gut fermentation and determined that a fibre-free diet could significantly reduce symptoms and intestinal gas. (9)

    A systematic review of the effectiveness of including different types of fibre in the diet of IBS patients being treated for constipation found only marginal benefits. In some cases, fibre actually worsened IBS symptoms. (10)

    The Digestive Wellness Eating Plan


    The first step of the eating plan is to reduce the consumption of fermentable carbohydrates.  Since we know that certain carbohydrates are malabsorbed by a large percentage of people with IBS, and that these carbohydrates feed bacterial overgrowths, it’s no surprise that studies show that removing foods that contain these carbohydrates from the diet will reduce symptoms of IBS.

    I have found that using a combination of the FODMAPs Diet, Specific Carbohydrate Diet, and the Fast Tract Diet provides the most effective approach to reducing digestive symptoms and this forms the first phase of the eating plan.

    It is important to note that, while removing fermentable carbohydrates will provide symptomatic relief for most people, it won’t address the underlying reasons for your symptoms, such as dysbiosis, SIBO or altered gastric secretions. The diet is mostly temporary and is designed to stop feeding the overgrowths of bacteria and/or yeast, and is most effective when used in conjunction with other treatments that address these conditions.

    The low FODMAP diet was never  designed to be a long term or lifestyle diet, it should be used to manage your symptoms whilst you treat the underlying cause. Read more about the down side of long term low FODMAP here.

    Other important goals of the diet are to reduce inflammation, assist the re-population of beneficial bacteria and to help repair the gut wall. In the second phase of our treatment plan, we carefully introduce certain medicinal foods, along with prebiotic and fermented foods, to further assist in this process.

    Making dietary changes can be challenging, so I have made the implementation of this IBS Diet as easy as possible, providing you with:

    • A list of safe foods
    • A list of foods to avoid
    • Sample meal plans
    • Meal planning template
    • A recipe book PDF with over 100 recipes
    • Ongoing challenging to fine tune diet

    Knowing what foods you should and should not be eating will give you a great sense of relief. As your treatment progresses and you start clearing up the cause of your symptoms, you will be able to re-introduce a lot of foods that you previously found problematic.