The FODMAP diet for irritable bowel syndrome (IBS)

The Irritable Bowel Syndrome (IBS) commonly creates abdominal pain, cramping, bloating, gas, diarrhea, constipation and/or nausea. These symptoms vary from person to person and may affect quality of life. Recent studies have suggested that some with IBS may respond, at least in part, to the FODMAP diet. And because some kids with Crohn's disease or ulcerative colitis have an irritable bowel too, the diet can sometimes help them too.

FODMAP stands for Fermentable Oligosaccharides, Disaccharides, Monosaccharides and Polyols. However, it is important to note that these FODMAPS sugars do not actually cause IBS, but they can trigger the symptoms. 

Specific Foods 

Fermentable sugars in the FODMAP diet include fructans and galactans (both Oligosaccharides), lactose (a Disaccharide), fructose (a Monosaccharide), And sugar alcohols (Polyols). 

Fructans and galactans are short-chains of sugar molecules that can be found in certain fruits, vegetables and legumes. They could also be found in certain grains, nuts and seeds. 

Lactose is a sugar naturally found in milk and dairy products, such as milk, cheese and yogurt. 

Fructose is a simple sugar, found in most fruits, some vegetables, sweeteners, high fructose corn syrup (HFCS) and some alcoholic beverages. 

Polyols are sugar alcohols. The two types of polyols known to cause GI symptoms are sorbitol and mannitol. Polyols can be found in some fruits and vegetables, and sweeteners. Polyols are often used in sugar-free products, such a sugar-free candy, chewing gum, mints, cough drops, and some medications. 

Getting Started 

Prior to starting the FODMAP Elimination Diet, it is important to consult with a gastroenterologist to rule out other medical conditions (because other conditions can have similar symptoms). Ideally a Registered Dietitian/Nutritionist (RD) should also be consulted to identify "high and low FODMAP foods". This is especially important for a child with IBS.

The elimination (or 1^st phase) of the diet is very restrictive. No foods that contain 'high FODMAP foods' can be eaten, typically for 2-6 weeks. The next step (challenge phase) involves working with a Dietitian to slowly and systematically reintroduce back into the diet 1 specific food (or food group) at a time. This will allow an understanding of which foods (or food groups) trigger IBS symptoms. Realize too that a large quantity of a 'low FODMAP' food may end up putting that food in the 'high FODMAP' category. 

Modifications for Children

A very restrictive diet, like the FODMAP, even if only for a limited time, may not be appropriate for children. For your child, the Dietitian may recommend a modified version of the FODMAP Elimination Diet. Because there are many ways to modify the FODMAP Diet, the Dietitian is able to adjust the diet according to individualized needs– where children are underweight, picky eaters, have limited food options (allergies, camp, college, school food) or those who have a history of eating disorders or disordered eating behaviors. Of course, some of those factors might apply to adults as well. 

Bottom Line

Given the science and potential complexities of following the FODMAP Elimination Diet, it is highly recommended that a registered dietitian meet one-on-one to customize a diet plan that works to meet each individual's preferences and needs.