The Different FODMAP Types for IBS Symptoms

FODMAPs are types of carbohydrates found in ordinary foods, and research suggests that they may contribute to symptoms in people who have irritable bowel syndrome (IBS). Eliminating high FODMAP foods from their diet helps many people with IBS feel better and may even have value for treating other conditions.

The acronym FODMAP stands for "fermentable oligosaccharides, disaccharides, monosaccharides, and polyols." These are all types of sugars that are poorly absorbed by the small intestine.

The Five FODMAP Types

FODMAP foods are broken down into five categories:

1. Fructans: Fructans are found primarily in wheat, many vegetables (most notably garlic and onions), and the food additives FOS and inulin. Fructans are non-digestible and thus are available to be acted upon by gut bacteria. The fermentation that results offers some health benefits but can contribute to unwanted symptoms in a person who has IBS.

2. Fructose: Fructose is the sugar found in many fruits, honey, and high fructose corn syrup. Fructose malabsorption is only a problem for some IBS patients.

3. GOS: GOS stands for galactooligosaccharides, which are sometimes called galactans. GOS can be found in legumes, including beans, chickpeas, and lentils. Like fructans, GOS are non-digestible and thus have similar effects on the body and in IBS patients.

4. Lactose: Lactose is the main sugar found in milk and other dairy products. Not all people with IBS are lactose intolerant. Foods also vary widely in lactose content, and therefore, some lactose-containing foods are allowed on the low-FODMAP diet.

5. Polyols: Polyols are sugar alcohols with scientific names that typically end in "- ol." They are found naturally in some fruits, such as blackberries, and vegetables, such as cauliflower and mushrooms, and are often used as artificial sweeteners. Two naturally occurring polyols are mannitol and sorbitol, and those added to foods include xylitol, maltitol and isomalt. (Note: Not all things ending in "-ol" are polyols.)

People who have IBS are typically not sensitive to every FODMAP type. Therefore, the low-FODMAP diet involves initially eliminating all of these types of FODMAPs, then re-introducing each type one at a time. The re-introduction is done in a careful and systematic way to see if the foods are tolerated or cause symptoms.

The ability to pinpoint which FODMAP types are troublesome allows you to eat as wide a variety of foods as possible. It's best to go through the elimination and challenge phases of the diet under the care of a qualified dietary professional.

The Monash University Low-FODMAP Diet App is an excellent resource for identifying the specific FODMAP content of common foods.

Frequently Asked Questions

How long does a FODMAP elimination diet take to figure out which foods trigger my IBS symptoms?

It can take approximately 6-8 weeks, or even longer, to work through an elimination diet and gauge your reaction to individual foods.

Are there over-the-counter medications for IBS?

Yes, nonprescription medications such as anti-diarrheal medication, laxatives, and probiotics, can be used for symptom relief. Your healthcare provider may also want you to try a low-FODMAP diet.