FODMAP intolerance is when certain carbohydrates cause digestive issues that can lead to gas, bloating, diarrhea, and more

• FODMAP intolerance is a condition where you have trouble digesting certain carbohydrates which can cause symptoms like bloating, gas, constipation, diarrhea, and vomiting.
• The culprit carbohydrates are oligosaccharides, disaccharides, monosaccharides, and polyols.
• To help relieve symptoms of FODMAP intolerance, try a type of elimination diet called the low-FODMAP diet that will help you identify exactly which foods are causing issues.
• This article was medically reviewed by Lisa Defazio, a registered dietician and nutritionist in Los Angeles, California.

No matter how good they taste, an ice cream sundae or a big slice of watermelon might send some people with Irritable Bowel Syndrome (IBS) running to the bathroom or clutching their stomach in pain.

Many people with IBS have trouble tolerating foods containing certain kinds of carbohydrates, or sugars. These carbohydrates are known as FODMAPs. FODMAP is an acronym that stands for Fermentable Oligosaccharides Disaccharides Monosaccharides and Polyols.

FODMAP intolerance is when you have difficulty digesting high FODMAP foods, which can trigger uncomfortable gastrointestinal symptoms like bloating, constipation, diarrhea, and pain. FODMAP intolerance tends to coincide with other gastrointestinal conditions like IBS, inflammatory bowel disease, and Crohn's disease.

FODMAP types and examples

FODMAPs are ubiquitous in all types of foods, so it can be difficult to know what exactly may be triggering your symptoms. Here's a break down of the different kinds of FODMAPS:

Oligosaccharides

Most types of oligosaccharides are indigestible, so they move through your small intestine to your large intestine, where bacteria finally break them down. They can help prevent constipation, but they can also cause bloating and gas.

Common foods that contain oligosaccharides are onions, garlic, wheat, rye, artichokes, and legumes.

Disaccharides

You may have heard of the three most common types of disaccharide: sucrose, lactose, and maltose. Lactose tends to be the culprit for most cases of intolerance. According to the American Chemical Society, as many as one in four adults is lactose intolerant.

Common foods that contain disaccharides include molasses, maple syrup, and ice cream.

Monosaccharides

These are your simple sugars, like glucose, fructose, and galactose. It tends to be easier for your body to digest glucose and galactose compared to fructose which can take longer.

Examples of foods that contain monosaccharides are fruit, honey, candy, and soft drinks.

Polyols

Polyols are sugar alcohols often used to provide a sweet flavor to foods. They also don't get fully digested in the small intestine, so they move to the large intestine, where bacteria begin the fermentation process, which often results in gas. They can also have a laxative effect.

Common examples of foods that contain polyols include peaches, plums, cauliflower, and mushrooms.

The FODMAP diet and road to relief

People with gastrointestinal conditions like IBS, IBD, and Crohn's disease are often counseled to avoid foods high in FODMAPS.

As the body processes the foods containing FODMAPs, some of them may ferment. As a result, your gut may fill with some extra fluid and gas and get a little bloated or distended, which can be painful for people who already have a sensitive gut.

If you have FODMAP intolerance, one of the best ways to avoid symptoms is to cut out the foods that trigger them. Or limit the amount you eat at one time, to reduce the likelihood that your body will react. A low-FODMAP diet may be just the ticket for you.

But it's figuring out what kind of intolerance you have that's the challenge.

Finding out which FODMAPs you can't tolerate is basically a process of elimination. Jesse Houghton, a gastroenterologist in Portsmouth, Ohio, explains that he typically advises people to eliminate FODMAPs from their diet for a few weeks, until their symptoms of discomfort are gone.

"I tell my patients to reintroduce the FODMAPs that they previously enjoyed eating, one at a time, for one to two weeks per food item," he says. "If their symptoms do not return, great! That item can be safely eaten from now on. If they feel one or more of their symptoms returning, that food item should be avoided long term."

However, when trying a low-FODMAP diet, Pillepich says "I would highly recommend working with a registered dietitian to implement this diet. The FODMAP categories are pretty random and not categorized in an easy-to-remember way. It is very helpful to work through this process under the guidance of a professional."

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• What is a low FODMAP diet and how it can help with gastrointestinal discomfort
• How to lose weight and keep it off with the right diet and mindset
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