The holidays are over. If you have irritable bowel syndrome (IBS), however, that holiday infusion of good, rich food may have left your gut bloated, gurgling, gassy, stopped up, or loosened up at some point.

IBS is a complex disorder that researchers are still learning about, but they’re pretty clear that four factors play a role: hypersensitivity reactions, increased gut transit time (motility), higher than normal amounts of fermentation, and malabsorption of sugar.


Bloating is a common symptom of IBS

Developed by Peter Gibson and Susan Shepherd at the University of Melbourne, Australia around 2000 and published in 2009, the odd-sounding FODMAPS diet addresses two of these factors: fermentation and sugar malabsorption.

The FODMAPS diet came out of the recognition that distension of the intestinal tract – probably caused by high rates of fermentation – is a source of pain in people with IBS. (Interestingly, the gases usually produced by this fermentation — hydrogen, carbon dioxide, and methane — are usually odorless.)

The FODMAPS diet works by reducing consumption of foods that are likely to cause fermentation in the gut.

What are FODMAPS?

Since no one in their right mind would make up the FODMAPS acronym, it’s no surprise that it refers to something scientific:

  • Fermentation – foods that cause fermentation. They include the following:
  • Oligosaccharides – composed of simple sugars, including wheat, rye, barley, onions, shallots, spring onions, garlic, legumes, lentils, artichokes, and chicory.
  • Disaccharides – foods containing double sugar molecules (lactose) such as milk, yogurt, and ice cream.
  • Monosaccharides – foods containing single sugar molecules (fructose) such as honey, corn syrup, mango, apples, pears, and watermelon.
  • Polyols – foods containing sugar alcohols — sorbitol, mannitol, maltitol, xylitol — such as stone fruits like avocados, cherries, peaches, plums, apricots, and nectarines.

Also included are high fiber foods.  High amounts of fiber also tend to produce fermentation. (Note that not all oligosaccharide- or disaccharide-containing foods cause fermentation, but some do.)

Successful Diet

Five studies suggest a FODMAPS diet can be very effective in reducing the symptoms of IBS. One study suggests it may be more effective than reducing gluten intake in people with non- celiac gluten sensitivity.

A recent study found that FODMAPS do, indeed, increase gut distension by causing increased gas (fermentation) and water content. The pain present in IBS is caused at least in part by a mixture of increased distension and increased sensitization.

Beating the Bloat- By FODMAPS creator Dr. Peter  Gibson

FODMAPS are foods that tend to be more poorly absorbed in the small intestine, possibly because you’re lacking the enzymes to do the job.  The central sensitivity present in IBS may also cause you to experience pain when others are not experiencing any.

IBS- Fluid

A healthy control and an IBS patient after ingesting an FODMAPS type substance

When the poorly-digested FODMAPS hit the colon, the bacteria have a field day and produce lots of gas.  These foods also tend to draw water into the large intestine reducing gut motility, causing swelling of the intestinal walls (bloating) and pain.

Researchers recently gave people with IBS and healthy controls an undigestible substance that passed pretty much intact into their large intestines where it produced gas, pain, bloating, etc. in the IBS patients, but not the healthy controls. The kicker was that the study, the first to demonstrate structural abnormalities in the guts of people with IBS, found increased water uptake in the guts of the IBS patients.

The Diet

Low and High FODMAP Foods (from Monash University)

Food Category High FODMAP foods Low FODMAP food alternatives
Vegetables Asparagus, artichokes, onions(all), leek bulbs, garlic, legumes/pulses, sugar snap peas, onion and garlic salts, beetroot, Savoy cabbage, celery, sweet corn Alfalfa, bean sprouts, green beans, bok choy, capsicum (bell peppers), carrots, chives, fresh herbs, choy sum, cucumbers, lettuce, tomatoes, zucchini.
Fruits Apples, pears, mangoes, nashi pears, watermelons, nectarines, peaches, plums Bananas, oranges, mandarins, grapes, melons
Milk and dairy Cow’s milk, yogurt, soft cheese, cream, custard, ice cream Lactose-free milk, lactose-free yogurts, hard cheeses
Protein sources Legumes/pulses Meats, fish, chicken, tofu, tempeh
Breads and cereal Rye, wheat-containing breads, wheat-based cereals with dried fruit, wheat pasta Gluten-free bread, sourdough spelt bread, rice bubbles, oats, gluten-free pasta, rice, quinoa
Biscuits (aka cookies in the US) and snacks Rye crackers, wheat-based biscuits Gluten-free biscuits, rice cakes, corn thins
Nuts and seeds Cashews, pistachios Almonds (<10 nuts), pumpkin seeds

The Low FODMAP IBS Diet: Ten Rules for Living With IBS

Among other suggestions, this doctor asserts that eating small meals, reducing fat intake, reducing stress, and avoiding artificial sweeteners are good additions to a FODMAPS diet.

Sample Low FODMAP meal ideas –  From Monash University

Breakfast Gluten-free or spelt toast with vegemite, strawberry jam (sweetened with sucrose)· Cereal (oats, porridge, cornflakes*, rice bubbles*)· Tea or coffee (lactose-free milk if you have lactose malabsorption)·  Serving of suitable low FODMAP fruit* add oat or rice bran for extra dietary fiber
Lunch Gluten-free or spelt sandwich with fillings (ham salad, tuna salad, cheese/salad, egg/ lettuce)·      Soup homemade with low FODMAP vegetables· Fresh salads with dressing (olive oil, lemon juice) and plain meat·  Gluten-free pizza with low FODMAP vegetable toppings
Dinner  Meat/fish/tofu plus low FODMAP vegetables/salad plus potato/rice/gluten-free pasta/rice noodles
Snacks One serving of suitable fruit (cantaloupe, banana, grapes, strawberries, orange)·  Yogurt (lactose-free if you have lactose malabsorption)·  Gluten-free biscuits and cakes


More Low FODMAPS Foods

Vegetables: bamboo shoots, bell peppers, bok choy, cucumbers, carrots, celery, corn, eggplant (aubergine), lettuce, leafy greens, pumpkin, potatoes, squash (butternut, winter), yams, tomatoes, zucchini (courgette)

Fruits: bananas, berries, cantaloupe, grapes, grapefruit, honeydew, kiwi, kumquat, lemon, lime, mandarin, orange, passion fruit, pineapple, rhubarb, tangerine


Yes. some good foods are left – but peaches are not one of them…

Protein: beef, chicken, canned tuna, eggs, egg whites, fish, lamb, pork, shellfish, turkey, cold cuts (all prepared without added FODMAP-containing foods), nuts, nut butters, seeds

Dairy and non-dairy alternatives: lactose-free dairy, small amounts of: cream cheese, half and half, hard cheeses (cheddar, colby, parmesan, swiss), mozzarella, sherbet, almond milk, rice milk, rice milk ice cream

Grains: wheat-free grains/wheat-free flours (gluten-free grains are free of wheat, barley and rye): bagels, breads, hot/cold cereals (corn flakes, cream of rice, grits, oats, etc.), crackers, noodles, pastas, quinoa, pancakes, pretzels, rice, tapioca, tortillas, waffles

Beverage options: water, coffee and tea (individuals with IBS may also want to limit caffeine), low FODMAP fruit/vegetable juices (limit to ½ cup at a time).

The FODMAPS Elimination and Reintegration Diet Plan

This diet can produce results quickly for some, but experts on different websites recommended a 2-8 week trial period. If all goes well, then you can attempt to reintroduce one FODMAP food at a time back into your diet in order to maintain as high a variety of foods as you can tolerate.

The FODMAPS diet isn’t curing IBS. If you have IBS and go back ona FODMAPS-rich diet, your gut will probably blow up again; it’s about removing foods that trigger it.  Going on a low FODMAPS diet, however, should allow you to later reintroduce some higher FODMAPS food sback into your diet, perhaps in smaller amounts than you were used to.

Your gut may also be sensitive to some categories and of some FODMAPS foods and not others.  Your gut may also be sensitive to foods not in the FODMAPS categories. I have problems, with bananas which are in the low FODMAPS category but do pretty well with apples which are in the high FODMAPS category. FODMAPS is a good beginning, but IBS is complex, not completely understood and surprises may be in store.

Dr. Peter Gibson (FODMAPS originator) – on the Diet and the Latest Science


Fructose – Possibly A Key Dietary Factor


Then there are the blueberries – a low glycemic indexv food with fairly high fructose levels (sigh)

Recent studies suggest that high fructose foods may be particularly adept at producing gut distension and symptoms. (See a list here.) After the high-fructose sweeteners used in carbonated drinks, alcohol, and sweets, the highest natural fructose containing foods are raisins, apples, pears, honey, grapes, and blueberries. Other common high fructose-containing foods are bananas, blackberries, cherries, figs, kiwis, mandarins, mangos, rockmelons, grapefruit, pineapples and raspberries.

Fructose is also common in vegetables. Some of the higher fructose-containing vegetables include asparagus, artichokes, beans, broccoli, leeks, cabbages, onions, tomatoes, peanuts, and zucchini.

These foods should be eaten with other foods to lessen their impact.

Watch Fats and Oils

Because fats and oils slow down gut motility – already a problem with IBS – reducing fat content may be helpful.

Fiber and Constipation

Like all the disorders we deal with, IBS is a complex one. Some people with IBS may benefit from high fiber diets while others will suffer while on them.  People who experience regular constipation might want to try adding 25 grams fiber daily for women and 38 grams for men, recognizing that they may experience more gas while on the higher-fiber diet.

If you’re constipated, an excellent way to relieve it without the straining that can cause hemorrhoids is: while you’re sitting on the toilet, put your hands on the outsides of your knees and then push against your hands with your knees while resisting with your hands.

The Wheat Question: Gluten or FODMAPS?

The originator of the FODMAPS diet, Dr. Peter Gibson believes that the relief that some or perhaps many people get from removing wheat from their diet is more due to reducing their FODMAPS intake than to any actual gluten sensitivity.

FODMAPS and Small Intestinal Bowel Overgrowth (SIBO)


Why do good diets sometimes fail in ME/CFS and FM? Possibly because of FODMAPS….

An excellent blog in the Paleo Leap website points out that the problems caused by FodMaps and SIBO are similar and often related, but they’re not the same. People with FODMAPS-caused problems experience difficulty with absorption and bacterial overgrowth in both the small and large intestines, while SIBO refers to bacterial overgrowth in the small intestine.  It’s possible to have FODMAPS issues without having SIBO, but if you have SIBO then a FODMAPS diet should help because it’s reducing bacterial overgrowth in the small intestine.

FODMAPS – Why Good Diets Sometimes Fail in IBS

The FODMAPS diet could also help explain why some people on otherwise good diets such as the Paleo and Mediterranean diets still experience gut problems.

Cause Unclear, but Gut Flora May Play a Role


Nobody knows why FODMAPS cause so much trouble for some people but the gut flora could play a role

Why some people have more problems with FODMAPS is not clear, but altered bacterial flora is a possibility. A recent review of the gut and fibromyalgia suggested that the FODMAPS, gluten, and lactose intolerance found fibromyalgia could result from gut infections for bacterial overgrowth. A recent small study suggests that a positive response to a FODMAPS diet may be more a function of altered bacterial flora than other factors.

The Diet for You?

Kicking out some of the good nutritious foods in this diet can be hard. I did it the hard way. Before I learned of the FODMAPS diet, I slowly, painfully, recognized that onions were a major problem for me. Apples I tolerate fairly well but have to watch because of their high sugar content. I gave up dairy over ten years ago.  I gave up beans about five years ago and eggs two years ago. Many of these foods (beans, eggs, onions, wheat) I was eating in high quantities and some I could probably introduce back in small amounts, but I’m still gassy and get bloated at times.

Some foods that are not high in FODMAPS, such as eggs and bananas, cause me gastrointestinal distress. Some low-FODMAPS but high glycemic foods such as potatoes cause me problems not with my gut but with my energy levels.

I seem to do best with my low FODMAPS, low glycemic, Paleo-type diet, but I’m still experimenting.


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