Kathleen M. Zelman, MPH, RD, LD
Louise Chang, MD
It's not easy to find the right diet
when you have irritable
bowel syndrome (IBS). Eating certain foods can cause major discomfort
for people with IBS, but figuring out which foods cause the symptoms is a
highly individual process.
WebMD consulted gastrointestinal nutrition expert Patsy Catsos, MS, RD, author of
IBS -- Free at Last!, for answers to your questions about diet and
irritable bowel syndrome.
Irritable bowel syndrome (IBS) is often defined as abdominal
pain and discomfort with altered bowel habits, in the absence of any other
medical explanation for the symptoms. Patients with IBS often report gas, bloating, diarrhea, or constipation.
Certain foods, like beans and prunes, can cause gastrointestinal effects in
most people. A certain amount of gas is normal and healthy. The average
person produces 1-4 pints a day and passes gas 14 times! It’s also normal
for the consistency and frequency of your bowel movements to vary
However, if you are experiencing abdominal pain, a change in your bowel
habits, or if your gas, diarrhea or constipation is interfering with your
normal activities, you should see a doctor. It's important for your health care
provider to help you rule out other problems, especially if you have any of the
In the diarrhea-prominent type of IBS, the primary form of treatment is
diet. Constipation can be more challenging to treat with diet alone. Other
forms of noninvasive therapy that are routinely used are physical therapy and
management, because studies show the mind-gut connection is very real.
Each person is unique. But in general, foods that are high in fat, fried
foods, spicy foods, alcohol, and caffeinated coffee and tea can be problematic.
Some foods, such as beans, cabbage, broccoli, Brussels sprouts, cauliflower,
peas, onions, and bagels, that can cause minor discomfort in a normal GI tract
can cause significant bloating, gas, and abdominal pain in IBS sufferers.
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.
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.)
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
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
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.
Health care providers have known for years about the GI impact of select
FODMAPS, such as lactose and sugar alcohols. Fructose and galactan intolerance
are a bit newer. Although it is very well accepted and widely practiced in
Australia, it is a new idea for most health care providers in the U.S.
The FODMAPS approach is unique because it views all of these carbohydrates
as one big system, looking at the forest instead of the trees. Some providers
are concerned that the FODMAPS is too complicated, but many patients are very
motivated and willing to do anything to feel better.
Gluten-free diets are very popular right now
for a wide variety of conditions. When you eliminate gluten, you also eliminate
wheat products that contain fructans, one of the FODMAPS carbohydrates.
Eating certain carbohydrates can cause gas, bloating, and watery diarrhea
for some IBS sufferers. Lactose, or milk sugar, is one example many people are
familiar with. If your bowel has difficulty tolerating lactose, when you eat it
-- especially in high doses or when you eat it alone -- bacteria in the large
intestine ferment it, and it can result in gas and painful bloating as well as
The use of probiotic supplements may help reduce symptoms in the long run,
but I would encourage using a FODMAPS approach before introducing probiotics into the diet.
Lactase is the name of the enzyme that breaks lactose
(milk sugar) down to simpler sugars during digestion. Using milk products that
have been pre-treated with this enzyme, or taking an enzyme, are good
strategies for reducing symptoms. Naturally fermented foods, such as yogurt and
kefir and hard cheeses, contain less lactose than milk and may be better
Use lactose-free or reduced-lactose dairy products; small servings of
berries and citrus fruits; potatoes, rice, oats and corn products; lean meats,
fish and poultry; salad vegetables; and plant-based oils. When it comes to
sweeteners, small servings of granulated sugar and maple syrup are usually
Keep your diet as varied and colorful as you can tolerate. Remember, you can
probably tolerate small servings of your favorite high-FODMAPS foods. Even if a
whole bowl of grandma’s baked beans is out of the question, a little bite won’t
Some people with IBS eliminate entire food groups to control symptoms. These
very limited diets can cause weight loss and at the other extreme, weight
gain. Unfortunately, some people with IBS find that the “healthier” they
eat, with more fruits, vegetables, whole grains, and milk, the worse they feel.
All of these situations can put them at risk for vitamin and mineral
deficiencies, which is why it's important to have a registered dietitian help
with the best dietary plan.
SOURCE:Patsy Catsos, MS, RD, author, IBS -- Free at Last!
The Health News section does not provide medical advice, diagnosis or treatment. See additional information.