What is the FODMaP diet?

The FODMaP diet is a guide to help decrease symptoms of irritable bowel syndrome (IBS).  The word “FODMaP” is made up of the first letters of the scientific names of certain types of carbohydrates that are found in foods (see below).  We often talk about carbohydrates as a single group.  There are actually different types of carbohydrates in different foods.  These different types of carbohydrates can have different effects on our digestive systems (the stomach, intestines, and other parts of the body that work together to digest food).  If you have IBS, then you probably already know that eating certain foods can cause more symptoms.  These can be bloating, gassiness, diarrhea, or constipation.  Research studies show that the FODMaP diet is a tool that can help decrease these symptoms.^1-3

How does the FODMaP diet work?

The diet works by cutting down or totally cutting out carbohydrates that might cause more symptoms.  Carbohydrates that don’t get absorbed well pass to the end of the intestine (the colon).  Decreasing these carbohydrates helps IBS symptoms in the following two ways:¹

• There are trillions of bacteria living in our intestines.  They are important for many things, including digestion and helping us get the nutrients we need from our food. (For more information, see the Whole Health handout “How a Healthy Gut Makes for a Healthier You.”)  Some bacteria use the process of fermentation.  This is the same process that brewers use to make beer.  As you can imagine, this creates gas.  Some people have no problem when gas is produced in the intestines.  People with IBS can be more sensitive to the gas, and it causes bloating.  Bacteria use the carbohydrates that pass into the colon for fermentation.  By decreasing the amount of carbohydrates that the bacteria can use, the FODMaP diet helps decrease the amount of gas and bloating.