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IBS Triggers

Loukia Lili, PhD

Irritable bowel syndrome (IBS) is a condition that affects the gut and manifests itself with a variety of unpleasant symptoms, including abdominal discomfort, pain, altered bowel movements, and noticeable mucus in the stool. Constipation, diarrhea, or a combination of these two typically occurs with the condition. Although not life-threatening, IBS is the leading cause of visits to the gastroenterologist.1

IBS is most prevalent in Caucasians but can affect any race. Females seem to be more susceptible than males, and the elderly suffer the least. Interestingly, research does not show any strong association with socioeconomic status, profession, or geographical location. Still, there is weak data that suggests the middle class has an estimated incidence rate of one percent per year worldwide. Of the middle class in the U.S., about 2.9 percent has IBS.

It's estimated that only about 10 percent of individuals with IBS seek medical care for the evaluation and treatment of their symptoms. Nonetheless, IBS accounts for 3.5 million physician visits in the United States annually and is the most common diagnosis in a gastroenterologist’s practice – accounting for about 25 percent of all patient visits.1

What triggers IBS?

Despite its high prevalence and the unpleasant, persistent symptoms that significantly impact the quality of life of all sufferers, IBS remains one of the most challenging conditions to treat. This is because the actual cause of IBS is still unknown within the medical and research communities. However, empirical data and observational studies have cataloged a list of the most common IBS triggers.

Excluding all pathologies related to the intestinal physiology – such as gastroenteritis or small intestinal bacterial overgrowth (SIBO) that can cause IBS symptoms – the most common IBS triggers are environmental, which means that they are from lifestyle and dietary habits.

Here are the most common IBS triggers:

The above triggers make a significant impact on the amount and composition of bacteria in your gut microbiome.

A recent review of over 1,000 clinical publications on IBS found that there are (at least) five main factors contributing to the development of IBS: 3

What can you do to avoid IBS flare-ups?

Nutritional habits

Let’s set the record straight. First, there is no scientifically sound evidence that individuals who suffer from IBS experience food allergies or intolerances. The cause and effect are hard to establish. Second, gluten may not be the [only] culprit in the debated new diagnosis of non-celiac gluten sensitivity (NCGS) in IBS patients. However, despite the contradictory results and arguable studies, there is experimental and clinical research work to demonstrate that particular dietary habits may reduce IBS triggers and flare-ups in some individuals who suffer from the condition.4

The following diets may have a positive outcome on IBS symptoms:

A Gluten-free and/or Dairy-free diet

Gluten is a substance present in certain grains and helps foods maintain their shape and elasticity. It is mainly found in wheat (bread, baked goods, soups, pasta, cereals, sauces, salad dressings); barley (malt, food coloring, soups, beer, brewer’s yeast); and rye (rye bread, rye beer, cereals). Dairy products are made from the milk products of animals. The most common dairy products come from cows, goats, or sheep and include milk, creams, cheeses, butter, yogurt, and desserts.

A gluten-free and dairy-free diet does not contain any of the above products or their derivatives. These kinds of dietary changes are not always successful or practical for everyone that has IBS symptoms. In special circumstances, some individuals have been known to develop nutrient deficiencies without a well-formulated diet plan.  

If you need to follow a gluten-free, dairy-free diet, here is a list of foods you can consume:

  • Wild caught fish, bone broth, and grass-fed meats/poultry
  • Healthy oils: Cold-pressed extra virgin olive oil, unrefined coconut oil, avocado oil, and expeller-pressed sesame oil
  • Dairy-free probiotic boosters and cultured food: pickled veggies, kefir water
  • Vegetables: leafy greens, cucumbers, celery, ginger, olives, artichokes, avocado, and red bell pepper. Starchy vegetables such as carrots, beets, potatoes, sweet potatoes, and squash are appropriate too.  
  • Fruits: darker fruits or berries (blueberries, strawberries, raspberries) contain less sugar to boost your antioxidant intake and are packed with vitamins
  • Eggs, as tolerated
  • Natural sweeteners: Maple syrup and honey (rich in minerals), molasses, and date sugar are appropriate on this diet; be sure to use in moderation
  • Herbs and spices: curry, turmeric, cumin, fresh basil, mint. These can support soothing the nervous and digestive systems and help support immune function.
  • Grains: quinoa, rice, gluten-free bread and pasta

Read more on a gluten-free diet from Mayo Clinic

Read more on a dairy-free diet from Mayo Clinic.

A Low-FODMAP diet

As it states in its name, a Low-FODMAP diet is one LOW in Fermentable Oligosaccharides, Disaccharides, Monosaccharides, and Polyols. What are these? FODMAPS are short-chain carbohydrates and sugar alcohols that are not well absorbed by the body and may cause abdominal pain. Limited studies have shown the potential benefits of this diet for IBS patients, but it seems effective for some, at least in the short-term.5

Here are some options to eat when following a low-FODMAP diet:

  • Fruits low in fructose: bananas, blueberries, kiwi, limes, mandarins, oranges, papaya, pineapple, and strawberries
  • Vegetables low in FODMAPs: bean sprouts, peppers, carrot, choy sum, eggplant, kale, tomato, spinach, and zucchini
  • Non-dairy milk or lactose-free dairy, which includes most hard cheeses
  • Meat, fish, chicken, eggs, soy, small servings of nuts and seeds
  • Rice, oats, quinoa

If you’re following this diet, you will want to avoid things with FODMPAS, which includes:

  • Fruits high in fructose: apples, apricots, cherries, figs, mangoes, nectarines, peaches, pears, plums, and watermelon
  • Vegetables high in FODMAPs: asparagus, Brussels sprouts, cauliflower, chicory leaves, globe and Jerusalem artichokes, karela, leeks, mushrooms, and snow peas
  • Beans, lentils
  • Wheat
  • Dairy products with lactose
  • Garlic, onion
  • High fructose corn syrup, artificial sweeteners

Stress management

Psychological stress and anxiety play a big role in IBS triggers and flare-ups. Studies have shown that IBS is a condition that results from a combination of irritable bowel and irritable brain.6

Managing stress can be achieved in many ways. Here are a few avenues:

  • Adjust your lifestyle so you can receive more high-quality sleep and stay on a routine. Think about using a white noise machine, taking a dietary supplement, and avoiding your phone, laptop, or TV before sleep.
  • Get regular exercise. Schedule time for yourself, get some basic equipment for your home, or join a group fitness class (in-person or online) and hold yourself accountable.
  • Try mindful practices such as meditation, yoga, and other relaxation breathing techniques.
  • Put a priority on the things that nourish your body and mind, whether that is visiting the spa, getting a massage, reading a book, walking in the park, going for a hike, or spending time with friends and family (in-person or online).

Get tested

One of the biggest challenges in managing your gut health is that the condition is truly unique to each individual. Trial and error through what triggers discomfort and what diet to follow can be costly, exhausting, and frustrating.

A simple solution for avoiding the trial and error process is to figure out how your microbiome is affected by your lifestyle and diet. A gut microbiome test that measures the DNA of the microbial community can provide that information.

GutbioTM by Onegevity is a test designed for individuals who want to optimize their gut health. It measures every microorganism from a stool sample and reports on all of the influential microbes associated with GI issues. And with personalized recommendations, you can optimize the amounts and ratios of bacteria towards a profile of healthy individuals.

If you are experiencing triggers from food or lifestyle habits that are causing occasional diarrhea, constipation, bloating, gas, or abdominal discomfort, a Gutbio report can provide personalized insights and actionable recommendations to reduce the time, money, and effort spent, and help resolve your problems.

Gutbio by Onegevity has science-based, physician-approved recommendations that are tailored to your unique profile and symptoms.


1.        CAMILLERI M, CHOI M-G. Review article: irritable bowel syndrome. Aliment Pharmacol Ther. 1997;11(1):3-15. doi:10.1046/j.1365-2036.1997.84256000.x

2.         Volta U, Pinto-Sanchez MI, Boschetti E, et al. Dietary triggers in irritable bowel syndrome: Is there a role for gluten? J Neurogastroenterol Motil. 2016;22(4):547-557. doi:10.5056/jnm16069

3.        Chey WD, Kurlander J, Eswaran S. Irritable bowel syndrome: A clinical review. JAMA. 2015;313(9):949-958. doi:10.1001/jama.2015.0954

4.         El-Salhy M, Gundersen D. Diet in irritable bowel syndrome. Nutr J. 2015;14(1):1-11. doi:10.1186/s12937-015-0022-3

5.         Halmos EP, Power VA, Shepherd SJ, et al. Diet low in FODMAPs reduces symptoms of irritable bowel syndrome. Gastroenterology. 2014;146(1):67-75. doi:10.1053/j.gastro.2013.09.046

6.        Qin HY, Cheng CW, Tang XD, Bian ZX. Impact of psychological stress on irritable bowel syndrome. World J Gastroenterol. 2014;20(39):14126-14131. doi:10.3748/wjg.v20.i39.14126