Up to 20 percent of Americans are estimated to have Irritable Bowel Syndrome (IBS). They put up with symptoms such as abdominal pain, bloating, and diarrhea. While there is no cure for IBS, it can be controlled by identifying personal food triggers.

Of those affected, emerging data suggests that up to 70 percent may find relief by following a low-FODMAP diet. Researchers at Monash University in Australia have been studying a group of short-chain carbohydrates that may be to blame. They're called FODMAPs, molecules found in foods that are poorly absorbed. Undigested carbs make their way from the small intestine to the colon where resident bacteria begin to digest them. But there's a slight problem. As the fermentation commences, gas is produced (ouch!). Plus, some of the sugars don't get digested. They stay in the colon where they attract water and the result is arguably the most inconvenient symptom of IBS—diarrhea.

FODMAP is an acronym for some long and difficult-to-pronounce words: Fermentable, Oligosccharides, Disaccharides, Monosaccharides, and Polyols.

Fermentable: The process through which gut bacteria degrade carbohydrates to produce gases (hydrogen, methane, and carbon dioxide)

Oligosaccharides: Fructans (found in wheat, rye, onions and garlic) and Galactans (found in beans and legumes).

Disaccharides: Lactose found in milk and dairy products.

Monosaccharide: Fructose found in honey, apples, high fructose corn syrups

Polyols: Sugars (sorbitol, xylitol, mannitol, erythritol) found in some fruit and vegetables and also used as artificial sweeteners.

Some patients have found that by restricting these sugars from their diet, their symptoms are alleviated. Also good to know: FODMAPS are cumulative and dose-dependent. So, you may able to have small amounts of one food, but eat more than you can tolerate and symptoms will appear.

Here's a list of common FODMAP foods from Monash University:

  • Vegetables: asparagus, onions, garlic, artichokes, sugar snap pea, onion and garlic salts, beetroot, Savoy cabbage, celery, sweet corn.
  • Fruits: Apples, pears, mango, watermelon, nectarines, peaches, plums
  • Milk and Dairy: Cow's milk, yogurt, soft cheese, cream custard, ice cream
  • Protein: Legumes and beans
  • Breads and Cereals: Rye, wheat-containing breads, wheat-based cereals with dried fruit
  • Nuts and Seeds: Cashews, pistachios

The University has developed an elimination diet that's being used worldwide to treat people with FODMAP sensitivity. By eliminating potentially problematic foods and reintroducing them—one at a time to your diet—you may be able to determine your trigger foods. However, the list of possible trigger foods is lengthy, and an individualized approach must be taken to be successful. That's why experts recommend enlisting the help of a dietitian experienced in FODMAPs.

Steven Lamm, MD, reviewed this article.




Tamara Duker Freuman. "IBS? Could be the FODMAPs." US News & World Report. Web. August 2012.

The Monash University Low FODMAP Diet. Web. 2010.

Irritable Bowel Syndrome. National Digestive Diseases Information Clearinghouse. Web. July 2012. http://digestive.niddk.nih.gov/ddiseases/pubs/ibs/