Low FODMAP Diet for IBS: Everything You Need to Know


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A low FODMAP diet is one of the most popular and frequently recommended treatments for IBS. If you’ve recently been diagnosed with irritable bowel syndrome, or you’re still seeking confirmation, then you’ve likely been recommended to try a FODMAP diet.

But it’s possible you don’t have any idea what it means.

FODMAPs are fermentable oligosaccharides, disaccharides, monosaccharides, and polyols. These short-chain carbohydrates are difficult to digest, and are absorbed poorly by the gut.

Because of this quality, they’re often thought to be possible causes of IBS symptoms. A low FODMAP diet promotes foods that contain less of these carbohydrates.

Introducing a low FODMAP diet for IBS can be difficult, but it may be the best way to get a handle on your IBS symptoms. Before you start, it’s essential to understand what FODMAPs are, what they do, and what foods they’re found in. This guide to the low FODMAP diet can help you get started.

Understanding FODMAPs

When you start properly managing your IBS, you’re going to come across the term FODMAP a lot. And it can be confusing.

To begin, let’s break down the acronym. FODMAP stands for: fermentable oligosaccharides, disaccharides, monosaccharides, and polyols. 

These are short-chain carbohydrates, and they tend to reach the large intestine and are fermented by the bacteria in the colon.

As they ferment, they draw in water and produce lots of gas. These gases force the gut to expand, leading to pain and discomfort.

FODMAPs can be both naturally occurring in foods, or used as additives. Some common foods containing the different FODMAPs are:

  • Oligosaccharides – Wheat, rye, garlic, onions, artichokes, legumes
  • Disaccharides – Fruits, dairy products such as milk and yogurt
  • Monosaccharides – Fruits, honey, and agave nectar
  • Polyols – Fruits, vegetables, and artificial sweeteners

As you can tell, FODMAPs occur in many foods. That’s why a low FODMAP diet can be tricky. It’s not about removing FODMAPs entirely, but finding the ones that are triggering your symptoms.

Starting a Low FODMAP Diet

Understanding what a FODMAP is can actually make starting the diet feel intimidating. FODMAPs find their way into such a large number of food groups, it can feel impossible to cut them all out.

The first thing you need to understand is that a low FODMAP diet is only a short-term consideration. This diet is highly restricted, and isn’t sustainable over a long time.

There are three stages to a low FODMAP diet:

Stage 1 – Elimination

The first stage of the diet involves eliminating high FODMAP foods from the diet.

Depending on the speed at which your symptoms ease, this stage can last for 3 to 8 weeks. If after 8 weeks you’re still struggling, speak to a healthcare professional.

Before starting the elimination process, you should always discuss it with a nutritionist or doctor to ensure the diet is right for you.

Stage 2 – Reintroduction

Once you’ve seen an improvement in IBS symptoms over the course of the elimination stage, it’s time to begin reintroducing foods.

Every 3 to 7 days, a new food should be added back to the diet, with careful monitoring of the symptoms. This is best done under the guidance of a nutritionist.

The purpose of the reintroduction stage is finding what foods you can tolerate, and in which proportions. If you develop symptoms, eliminate that food again, and once you feel better, try reintroducing another food.

Stage 3 – Personalization

At the third stage, FODMAPs will still be restricted, but you can better understand which ones trigger a reaction. This is also known as the maintenance phase.

The diet will be close to normal, only lacking the high FODMAP foods that triggered symptoms in the reintroduction phase. Over time, the diet may need to change again.

What Foods are High in FODMAPs?

High FODMAP foods to avoid eating are:

  • Vegetables such as artichokes, asparagus, cauliflower, garlic, onions, snow peas, and brussels sprouts
  • Fruits such as apples, watermelon, blackberries, peaches, prunes, pears, and dried fruits
  • Dairy products such as cow’s milk, ice cream, yogurt, and soft cheese
  • Starches such as wheat, barley, rye, cereals, pasta, and pizza
  • Nuts and fats such as cashews, pistachios, and avocados
  • Beans and lentils
  • And sweeteners such as agave nectar, honey, high fructose corn syrup, xylitol, sorbitol

Avoid meats such as sausages. Other high FODMAP foods to stay away from include battered or breaded meats and fishes.

What Foods are Low in FODMAPs?

Low FODMAP foods to construct a diet around include:

  • Vegetables such as bean sprouts, bell peppers, carrots, cucumbers, chives, eggplant, tomato, zucchini, spinach, and kale
  • Fruits such as bananas, blueberries, kiwi, lime, oranges, strawberries, grapes, and pineapple
  • Dairy products such as feta, brie, almond milk, rice milk, and soy milk.
  • Starches such as rice, quinoa, oat, and potato. Look for gluten-free breads and pastas as well
  • Nuts and fats such as peanuts, macadamia nuts, pumpkin seeds, pine nuts, walnuts, and almonds (limit to no more than 15 at a time)
  • Proteins such as tuna, chicken, beef, salmon, shrimp, eggs, and tofu

Be sure to check the ingredients list on products before you buy. FODMAPs are often used as additives, and may appear in some surprising places.

Gluten isn’t a FODMAP, but gluten-free foods do tend to be low in FODMAPs. 

Research and Benefits of a Low FODMAP Diet for IBS

Research into low FODMAP diets as a treatment for IBS is still ongoing. Many studies do indicate that adopting a low FODMAP diet can be a good way to manage the symptoms of IBS.

In a 2014 study, a low FODMAP diet was shown to reduce bloating, pain, and passage of gas. Patients using the low FODMAP diet also felt stool consistency was improved.

The evidence suggested that a low FODMAP diet was a good initial treatment for IBS.

Up to 86% of patients in a 2016 report found that following a low FODMAP diet could effectively reduce symptoms of IBS.

The study also found that a low FODMAP diet could be beneficial for a range of IBS related symptoms, such as pain, flatulence, diarrhea, and constipation.

It also recommended adopting the diet with the help of a dietary specialist, to ensure success.

A 2017 study also felt that a low FODMAP diet was beneficial to the majority of those suffering with IBS. Another 2017 report found similar results.

Research into a low FODMAP diet as a treatment for IBS is strongly supportive. Adopting a low FODMAP diet can be beneficial for a range of symptoms commonly associated with IBS.

By carefully controlling intake, a person can find a diet best suited to their own condition.

Should You Try a Low FODMAP Diet?

A low FODMAP diet should only be used by those with IBS who are looking for a way to better control their symptoms.

Due to the significant restrictions, those without IBS should not attempt a low FODMAP diet.

If you’ve found your IBS isn’t responding to other treatments and dietary changes, then a low FODMAP diet may be the next step.

Always speak with a doctor or nutritionist before attempting the elimination and reintroduction stages. 

Low FODMAP diets require preparation and research. If you intend to start, you have to be committed, or you won’t be able to feel the effects.

Conclusion

A low FODMAP diet can be an effective method of managing IBS. By cutting out foods that are traditionally hard to digest, and slowly reintroducing them, it’s possible to get a good understanding of what foods might be triggering your symptoms. 

Here are other Low FODMAP and food related articles:

Medically Reviewed and Written By

  • Julie Guider, M.D.

    Dr. Julie Guider earned her medical degree from Louisiana State University School of Medicine. She completed residency in internal medicine at the University of Virginia. She completed her general gastroenterology and advanced endoscopy fellowships at University of Texas-Houston. She is a member of several national GI societies including the AGA, ACG, and ASGE as well as state and local medical societies.

  • Kelly Chow

    Kelly first experienced IBS symptoms at the age of 24 with major-to-severe symptoms. She underwent all types of tests and experimented with many treatments before finally finding ways to manage her symptoms. Kelly has written and shared ebooks and Gluten-Free diet plans that she has used to live life like she did before IBS.

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