Irritable bowel syndrome (IBS) is a group of symptoms that affect your large colon, including abdominal cramping, bloating, abdominal pain, flatulence, diarrhea, and/or constipation.
Irritable bowel syndrome (IBS) affects 3-15% of people based on various criteria.
Symptoms are thought to be caused by ingestion of certain types of carbohydrates called short-chain carbohydrates. These are fermentable oligosaccharides, disaccharides, monosaccharides, and polyols, also known as FODMAPS.
These include the commonly known carbohydrates fructose and lactose. Ingesting these types of foods may be poorly absorbed in the small intestine, causing fluid to ender the bowel causing a rapid transit through the gastrointestinal (GI) tract.
When the FODMAPS reach into the large intestine, they are fermented, which leads to IBS symptoms.
What is Low FODMAP diet?
Researchers from Monash University in Australia developed an elimination diet called the Low FODMAP diet with conclusions the diet had improved symptoms in 68-76% people suffering from IBS.
Eliminating these types of foods helped decrease symptoms experienced from digesting.
The low FODMAP diet limits foods high in:
Found in dairy products such as milk, yogurt, and ice cream, cottage cheese, custard
It’s familiar sources coming from fruits like apples, watermelon, mangoes, and pears.
Packaged products such as high fructose corn syrup.
It’s familiar sources coming from wheat, barley, inulin, and rye.
Sources that include beans, almonds, and pistachios
It includes certain fruits like apricots,pears and vegetables like cauliflower and mushrooms. Sugar alcohols from sugar-free foods like mannitol, sorbitol.
What are the key concepts of the Low FODMAP diet?
A strict low FODMAP elimination diet is recommended to be followed for 6 weeks. Restricting only one FODMAP group is generally unhelpful in finding relief. If no improvement is seen at this point, the diet may not be beneficial. This is a short term elimination diet and best to work with a registered dietitian for implementation.
What are the common foods to eat and avoid on a Low FODMAP diet?
A list of common foods to eat & avoid:
|Foods to Avoid||Foods to Eat|
|Fruits – Apples, Mangoes, Pears, Cherries, Watermelon, Blackberries.||Fruits – Bananas, Blueberries, Strawberries, Raspberries, Grapefruit, Melon, Oranges.|
|Vegetables – Avocados,Asparagus, Artichokes, Onions, Garlic, Cauliflower, Mushrooms, Beans green, chicory.||Vegetables – Cucumbers, Green Beans, Peppers, Carrots, Dark Green Leafy Greens, Potatoes.|
|Dairy – Cow’s milk, Soft cheeses, Ice cream, Soy milk.||Dairy – Lactose free milk and yogurt, Hard Cheese.|
|Grains – Wheat, Barley, Rye||Grains – Gluten Free Breads, Rice, Quinoa, Cheerios (plain), Oats (plain or old fashioned)|
|Nuts – Cashews and Pistachios||Nuts and Seeds – Pumpkin Seeds, Sesame Seeds, Sunflower Seeds, Walnuts|
|Sweetners – Packaged products containing High Fructose Corn Syrup- Sugar Alcohols (Sorbitol, Mannitol, Xylitol, Isomalt), Honey||Protein – Meat, Fish, Chicken, Pork, Tofu (firm), Tempeh, Eggs|
|Fats and Oils – Olive Oil and Butter.|
What are the consequences of following the diet?
Going out to eat
Resources on implementing diet
If followed incorrectly, this diet may lead to constipation if not enough fiber is consumed. Fiber comes from whole grains, fruits, vegetables, and beans and according to the Institute of Medicine you should be getting at least 25 grams daily for women and 38 grams for men.
Increase your intake of low FODMAP fruits, vegetables, and whole grains that are gluten-free such as brown rice or quinoa to get enough fiber in addition to drinking plenty of water.
This diet may be tough to follow closely if you plan on going out to eat. Foods generally avoided include sauces, dressings, and marinades, cream-based dishes, foods containing gluten and broth-based dishes (due to onion and garlic).
Take a look at the menu if it is available online so you can get an idea ahead of time on what to order. When in doubt, request a piece of chicken or steak without marinade with a side of plain steamed vegetable and baked potato or ask for a salad with lemon juice and olive oil for your dressing.
Be sure to avoid dried fruit, croutons, onions, apples, cashews, and pistachios.
You have to be very careful about packaged products when following this diet. Generally, sneaky ingredients include dried fruit, high fructose corn syrup, milk, and chicory (to boost fiber- found in many high fiber cereals and snack bars), onions and garlic.
Beginners may find that it’s best to avoid packaged products while they learn all of the foods that typically cause IBS symptoms.
This diet encourages gluten-free foods NOT due to gluten, a group of proteins found in grains, but due to the types of sugar found in naturally gluten foods, including wheat, barley, and rye. This diet encourages reductions of these grains but does not require you to avoid all foods containing gluten strictly.
If you feel that you would benefit from following the Low FODMAP diet due to IBS symptoms, there are resources to help. Monash University created its app called the Monash University Low FODMAP Diet App that is maintained by researchers who developed the diet. They provide up-to-date information on new foods testing content of FODMAPS.
The best way to go about going on this diet is being prepared. It is helpful to make a grocery list of appropriate foods with a meal plan ahead of time for the week, so you are not left in a bind with what to eat as this diet has many restrictions.
At the end of 6 weeks, foods should be reintroduced slowly. A food diary helps track what foods you can tolerate and in what quantity. Risk of following this diet long term without proper guidance may lead to nutritional deficiencies.
To reiterate, working closely with a dietitian is best in both implementing this diet and reintroducing foods as this is not meant to be a long term diet.
 Caroline J Tuck, Jane G Muir, Jacqueline S Barrett & Peter R Gibson (2014) Fermentable oligosaccharides, disaccharides, monosaccharides and polyols: role in irritable bowel syndrome, Expert Review of Gastroenterology & Hepatology, 8:7, 819-834,DOI: 10.1586/17474124.2014.917956
 Diane Quagliani MBA, RND, LNDand Patricia Felt-Gunderson, MS, RDN, LDN Closing America's Fiber Intake Gap Am J Lifestyle Med. 2017 Jan-Feb; 11(1): 80–85.