FODMAPs are short-chain carbohydrates found in commonly eaten foods such as pasta, bread, onions, garlic, beans, milk, apples, honey and mangoes.

Instead of being properly digested and absorbed, FODMAPs travel through the gastrointestinal tract, drawing excess fluid into the small intestine and generating gas when they are fermented by bacteria in the large intestine.
The fluid and gas build-up caused by undigested FODMAPs pushes on the walls of the intestines, causing uncomfortable symptoms and altered bowel habits in susceptible individuals.

The low FODMAP diet for IBS was first defined in 2004 by researchers at Monash University, Australia. It categorizes foods that trigger gastrointestinal problems according to the type of carbohydrate they contain, i.e., Oligosaccharides, Disaccharides, Monosaccharides, and Polyols. This makes it possible to systematically test one group of food at a time, instead of individual items.

Before the advent of the low FODMAP diet, people were handed a long list of seemingly unrelated foods and instructed to avoid the ones they felt were causing their symptoms. Not only was this confusing, it also did not provide an orderly way of assessing one’s tolerances.

 

Many low and high FODMAP foods lists are available online, but they are not updated regularly, and often contain conflicting advice.

For the most accurate and comprehensive information, check out the Monash University Low FODMAP Diet App. It provides the FODMAP content of hundreds of foods, including certified low FODMAP products such as bread, crackers, snacks, and condiments. This Monash University Low FODMAP Diet App is an indispensable tool for people who are following the low FODMAP diet for IBS.

Since its inception, the low FODMAP diet has been subjected to numerous clinical trials, and has become the go-to dietary intervention for irritable bowel syndrome, or IBS. Studies show that foods for IBS provide relief for up to 75% of people suffering from the common disorder, which is characterized by recurrent episodes of lower abdominal pain, bloating, diarrhea and/or constipation.

IBS is considered to be a functional disorder, which means that the symptoms are real, but no tissue damage, structural abnormalities, or biochemical changes are found on examination. However, IBS can impact your day-to-day living in a number of areas, including social life, your career, relationships, and family time.

Proper diagnosis by a gastroenterologist is very important, because IBS symptoms are shared by more serious gastrointestinal disorders such as celiac disease, ulcerative colitis, Crohn’s disease and colon cancer.

[OPTIONAL: In addition to IBS, the low FODMAP diet shows promise for helping people with other digestive disorders, including small intestinal bacterial overgrowth (SIBO).]

The low FODMAP diet is very effective, but only if you follow it correctly. Because of its complexity, the folks at Monash University stress that it is best undertaken with supervision by a Registered or Licensed Dietitian who specializes in gastrointestinal conditions and foods for IBS.

Elimination: During this phase, high FODMAP foods are avoided until symptoms are eliminated or significantly reduced. This can take anywhere from two to six weeks, depending on severity of symptoms and ability to adhere to the FODMAP elimination diet.

Challenge/Reintroduction: In the challenge/reintroduction phase, High FODMAP foods from each group are added back from the initial FODMAP elimination diet step in a controlled fashion. There are many ways to approach this, but it is important to challenge only one type of FODMAP at a time. For instance, when testing oligosaccharides, the rest of your diet should not contain other FODMAPs or it will be impossible to tell which one is responsible for your symptoms.

Integration: Once you have determined which FODMAP group(s) are a problem for you, it’s time to integrate what you’ve learned into your everyday life. It's important to remember that your ultimate goal is to include as many nutritious FODMAP foods in your diet as you can, because total avoidance is neither healthy nor practical.

In some ways, this is the hardest phase of all, because there’s no one roadmap that will be right for everyone. The good news is, there are more low FODMAP recipes, packaged foods, and other resources available to help you on your journey than ever before.

For more detailed information about the low FODMAP diet, we've broken down each phase in detail here. 

First, take a deep breath! Seriously…stress can trigger tummy trouble, so try not to get overwhelmed before you even start the low FODMAP diet.

Next, contact a knowledgeable dietitian to help guide you through the process. This may seem indulgent or unnecessary considering how much information is available online, but it will ensure that you are following the three phases of the diet correctly. If you feel confident that you can go it alone, try to wait until you have time to mentally and physically prepare yourself. You’ll be much more successful if you understand the low FODMAP concept, are aware of which IBS foods to avoid, have collected some good low FODMAP recipes, and have stocked your kitchen with low FODMAP foods.

Maybe, maybe not. Persistent symptoms are often due to dietary indiscretion, either intentional or not. If you are eating too many high FODMAP foods, IBS foods to avoid, or frequent, large portions of low FODMAP foods, then the diet is obviously not the culprit. Detailed food records should be able to reveal whether the problem is due to dietary “slippage,” or if something else it to blame. A dietitian with expertise in the Low FODMAP diet and foods for IBS can be very helpful with this, and may also be able to offer additional remedies or a different approach. If nothing seems to be helping, you may want to see your gastroenterologist again, or seek a second opinion, to verify the original diagnosis of IBS.

A Low FODMAP elimination diet is not one diet, even though it’s often portrayed that way. It's one of three distinct and equally important parts of a complete low FODMAP diet.

The FODMAP Elimination diet phase, which is what most people think of when they hear the term low FODMAP diet, was never meant to be followed indefinitely. After you have achieved symptom relief during this phase, it’s time to systematically test one FODMAP group at time in order to discover which FODMAPs are problematic for you; this is the Reintroduction/ Challenge phase.

The Integration phase is the diet you will follow “forever.” It will be uniquely yours; it may change over time, and it will most certainly contain some high FODMAP foods. The type and amount of these foods varies from person to person depending on a number of factors, including which foods provoked symptoms during the Challenge phase.

You can be successful on the low FODMAP diet if you’re a vegetarian or a vegan, but it may be more difficult for you than your carnivorous friends. Remember, FODMAPs are only found in foods that contain carbohydrates, such as grains, vegetables, beans, nuts, seeds and fruit – all of which are staples of a healthy vegetarian diet. Meat, fish, and poultry, on the other hand, are composed of protein and varying amounts of fat. Animal foods are not only FODMAP-free, their high protein content also makes them very satiating, and this helps makes the diet easier to follow. Good sources of vegan low FODMAP protein include tofu, tempeh, canned lentils and chickpeas, quinoa, buckwheat groats and flour, soymilk made from soy protein, and certain nuts and seeds. Information about portion sizes for these foods is available on the Monash University Low FODMAP Diet App. Lacto-ovo vegetarians can get additional protein from eggs; lactose-free milk, yogurt and cottage cheese; and low-lactose cheeses such as cheddar, Swiss and feta.