Finding the Right Diet for IBS
Expert Patsy Catsos, MS, RD, answers questions about eating for IBS.
What is the best diet for people with IBS symptoms?
There is no one-size-fits-all diet. A proper diet for IBS is highly individualized.
A high-fiber diet was thought to be the best diet for almost everyone with IBS, but recent studies have shown that this isn’t true for everyone.
For people with constipation, it's common to try a high-fiber diet of 25 grams daily for women and 38 grams for men to see if that helps. People should eat as much dietary fiber as they can tolerate, and understand that a certain amount of gas production is a sign of healthy gut microbes at work.
The challenge is finding an acceptable fiber intake without experiencing debilitating abdominal pain and bloating, and frantic dashes to the toilet. And sometimes focusing on fiber alone doesn’t address the removal of potential trigger foods from the diet.
What's the best diet approach if you suspect you have IBS?
Eating smaller, more frequent meals spread throughout the day instead of larger meals can lead to less discomfort for some people. What is really important is to identify the foods that are causing the symptoms.
For individuals with diarrhea, gas, or bloating, or if a high-fiber diet fails, I suggest a two-week trial FODMAPS elimination diet. (FODMAPS stands for fermentable oligo-, di-, and monosaccharides and polyols.)
What is the FODMAPS approach?
You'll work with your physician and registered dietitian to eliminate all foods that contain the five forms of carbohydrates (lactose, fructose, fructans, sugar alcohols, and galactans) for a trial period of 1-2 weeks. If FODMAPS carbs are causing the symptoms, relief can occur in just a few days.
You follow the elimination period with a challenge of reintroducing one of the FODMAP carbs and observe symptoms. Additional FODMAP carbs are slowly added back, one at a time. At the end of the reintroduction phase, a final diet emerges with only those FODMAP carbs that are fairly well tolerated.
The goal is to find the most liberal and varied diet possible that still keeps symptoms under control. Most people find they can still include their favorite foods if they exercise care. For example, a person who discovers that fructans (found in wheat) cause a lot of distress might find they can’t tolerate wheat at every meal, but may be able to tolerate one portion of wheat without a problem.