8 Ways to Increase Fiber Without Making Bloating Worse
If you’ve been diagnosed with IBS, you have probably read a thing or two about fiber when trying to figure out how to manage your symptoms. But the thing is: fiber can be your best friend or your worst enemy when it comes to IBS. Especially if you don’t understand the differences between the different types of fiber.
This post is meant to help clear up some of that confusion so you can add fiber the right way – a way that supports digestive health and healing, rather than making your IBS worse. Read on to learn more!
What is fiber anyway?
Put simply, dietary fiber is a type of carbohydrate found in plant foods. It is resistant to digestion and absorption in the small intestine.
Dietary fiber has a lot of benefits for digestive health:
It acts as a source of energy to promote healthy bacteria in the gut;
It increases the release of digestive enzymes from the pancreas to break down carbohydrates, fats, and proteins in the food we eat;
It speeds up the time it takes for stool to pass through the gut which makes it effective for treating constipation;
It increases stool weight because it retains water which makes it effective in treating diarrhea; and
It binds to and removes toxins from the body.
And, it does so much more! But let’s stay focused…
Why does fiber make me gassy and bloated?
Dietary fiber is often classified based on how much moisture it is able to retain: this makes it soluble or insoluble. However, fiber can also be categorized based on its fermentability (the rate and extent to which a fiber is broken down by your gut bacteria).
While there are still a lot of gaps in research, current science suggests that, for people with IBS, the readiness of a fiber to ferment in the gut may be more important than its ability to dissolve in water. Fiber that is known to resist fermentation is known as low FODMAPs fiber. Fiber that readily ferments is known as high FODMAP. (FODMAPs stands for fermentable oligosaccharides, disaccharides, monosaccharides and polyols. These are short-chain carbohydrates that can be difficult for some people to digest.)
Because fiber resists digestion as it passes through the small intestine, it reaches the large intestine mostly intact. Fermentation occurs here when the undigested carbohydrates are fermented or metabolized by the gut bacteria in the colon. Unfortunately, a byproduct of fermentation is gas, and this is what can aggravate your IBS symptoms.
While these fermentation byproducts may not make you feel so good if you have IBS, I want you to know that fermentation is not a bad thing!
This process produces short-chain fatty acids, such as butyrate, which serve as the main form of energy that feeds the cells in your colon. Short-chain fatty acids are essential for a healthy gut. So, the key for individuals with IBS is finding balance.
How to ‘do’ fiber if you have IBS
To avoid the unpleasant side effects of gas, bloating, constipation, or diarrhea that can sometimes accompany the addition of fiber to the diet, here are a few tips.
Keep in mind that no two guts are alike, and some women with IBS may have lower or higher tolerances for different fiber substances and different amounts of fiber. It may take some experimenting to see what works best for you.
Based on the scientific literature, here are some key take-aways for bringing more fiber into your life.
1. Recommended daily intake of fiber is 25g per day for women. Regardless of an IBS diagnosis.
Fiber is an important dietary component for all individuals. Not just those with IBS. If your diet is rich in plant foods, you are probably meeting your daily requirements for fiber. If it’s not, it may be time to look at bringing more fiber into your life to support a healthy gut.
2. Start slow and gradually bump it up. Aim for 20-30g of fiber per day.
Most people cannot tolerate a sudden increase in fiber, especially for those with constipation. Adding too much fiber too quickly can cause increased gas, flatulence, and bloating; and, it can even worsen constipation. Aiming for 20-30g per day should be a guideline, rather than a hard and fast rule as each person’s gut will have different gut bacteria, and therefore, different fiber needs.
To avoid this, start by adding easily digestible fibers to your diet, and limit your consumption of fiber from raw vegetables. Start with soluble, low FODMAP fibers, such as psyllium, chia seeds, cooked veggies and fruit, and oatmeal. Once these foods are well tolerated, you can experiment with introducing more raw foods, fibrous vegetables, nuts and seeds, and more variety to your whole grains (stay away from wheat and wheat products though as this fiber ferments readily in the gut!).
3. Drink more water when you add more fiber.
When you are increasing your fiber intake, it is equally as important to make sure you are drinking enough water. This means at least 8 cups of water per day, if not more.
Fiber absorbs water causing it to form a gel-like substance which makes your stool bulkier and more easy to pass. However, if you are not drinking enough water, this can actually cause the fiber to act more like a gum that sticks to the colon and can contribute further to bloating and constipation, rather than relieve it.
4. Research shows that soluble, viscous fibers that have a low rate of fermentation (e.g. psyllium) may be most beneficial for both constipation and diarrhea in IBS patients.
See list of foods below.
5. Try increasing fiber first thing in the morning.
When introducing more fiber into your diet, consuming high fiber foods first thing in the morning lowers your chances of experiencing gas and bloating from fermentation because the burden on your digestive tract is lower on an empty stomach.
6. Be mindful of stacking large amounts of high FODMAP fibers with other high FODMAP foods.
This can significantly increase the amount of gas produced following a meal, and it may explain why some higher fiber foods are okay for you to eat at one meal but give you problems at another.
Learn more about “stacking” here.
7. Individuals with IBS-constipation may need up to 30-50g of fiber per day while those with IBS-diarrhea may need to limit their consumption to 20-25g.
Increasing soluble fiber is especially important for those with constipation. Again, be mindful of whether or not the foods you are choosing are readily fermentable. Psyllium, cooked veggies, fruit or pureed fruit juices, oatmeal and chia seeds are good options.
Too much fiber may contribute to diarrhea, and limiting insoluble fibers such as those from raw vegetables, fruits peels and seeds, nuts and seeds, dark-grained rice, and wheat bran may be helpful. Introducing soluble fiber instead, which helps retain liquid in the gut, may also improve stool consistency with diarrhea.
8. It is best to get your dietary fiber from food but fiber supplements can be a good choice, especially for those with constipation.
Not all fiber supplements are IBS-friendly so choose wisely – and drink LOTS of water with it to avoid constipation.
Look for fiber supplements containing psyllium or partially hydrolyzed guar gum (one of my favs is Genestra’s Herbal Bulk which has psyllium, oat and rice bran, apple pectin, and guar gum).
Avoid products that contain inulin, wheat-bran, or FOS (fructo oligosaccharides). These are readily fermentable fibers and can increase gas and bloating.
Do not use fiber supplements if you have been diagnosed with a blockage in the colon.
Fiber supplements can be useful but using them to excess can also affect the absorption of vitamins and minerals. Always talk to your trusted health care professional before using a fiber supplement.
What fiber should I eat?
As mentioned, each individual will have different tolerances for different foods, so you’ll have to experiment with what works for you and your gut.
Generally, soluble, low FODMAP fibers are best for IBS, and this is the best place to start when bringing more fiber into the diet. Insoluble, low FODMAP fibers may have varying levels of tolerance, depending on the person and their gut. Same goes for the high FODMAP fibers. Play around within each category and see what works best for you and your gut.
* Scientific studies have shown benefits for IBS with use of ground psyllium or ground flaxseed. It is important to work up to the recommended dosage gradually over a period of several days or even a few weeks, depending on the person. Psyllium and ground flaxseed are best taken first thing in the morning on an empty stomach with plenty of warm water (not hot, as this can cause clumping) – at least 16 ounces.
** Wheat bran is often recommended as a fiber supplement, but wheat is highly fermentable and not recommended for those with IBS.
RESOURCES
The Effect Of Fiber Supplementation On Irritable Bowel Syndrome: A Systematic Review And Meta-analysis, 2014. https://pubmed.ncbi.nlm.nih.gov/25070054/
An Overview of Fiber and Fiber Supplements for Irritable Bowel Syndrome, 2019. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6676347/
More than FODMAPS: Fermentable Fibers and IBS. https://www.monashfodmap.com/blog/more-fodmaps-fermentable-fibres-ibs/
Best Management of Irritable Bowel Syndrome. https://fg.bmj.com/content/12/4/303
“The Bloated Belly Whisperer” by Tamara Freuman
Igg Food Antibody Guided Elimination-Rotation Diet Was More Effective than FODMAP Diet and Control Diet in the Treatment of Women with Mixed IBS-Results from an Open Label Study. https://pubmed.ncbi.nlm.nih.gov/34640335/
Irritable Bowel Syndrome and Dietary Interventions. https://pubmed.ncbi.nlm.nih.gov/34640335/
The Effect Of Fiber Supplementation On Irritable Bowel Syndrome: A Systematic Review And Meta-Analysis. https://pubmed.ncbi.nlm.nih.gov/25070054/
