The Best Fiber Supplement for IBS-D +8 Brands to Choose

Image of a variety of fiber powders in blue scoops on a white background with wording The Best Fiber Supplement for IBS-D by The Healthy RD

The best fiber supplement for IBS-D is definitely going to be one that is rich in soluble fiber, but that is not the whole story.  

Supplementing fiber requires good fiber-know how.

Additionally, there are several types of fiber from natural sources that you may want to give a try (and those to avoid) if you struggle with IBS-diarrhea predominant symptoms.

It is also important to note that, while fiber can be a godsend for many people’s IBS-D, there are some rules to follow when first embarking on fiber supplements.

I will review those for you in this post.

Contains affiliate links.  Visit the disclosure page for more information.  

Best fiber supplement for IBS-D brands at a glance:

If you don’t have time to read the whole post, here is a quick overview of the best fiber supplements for IBS-D.  Still, I do recommend that you read the fiber precautions section before buying anything. 

Fiber precautions

Increasing fiber intake is normalized in our society. 

But I want to warn you that fiber supplements come with more risk than some other digestive supplements like digestive enzymes, probiotics, and things like ginger for digestion.  

This is because, while most people need more fiber, they often go about it too quickly. Or, people don’t drink enough water, often choose the wrong form of fiber, or are completely sedentary after taking it.  

Overdoing fiber, especially with IBS patients, can actually be quite painful unless you do it right. 

In other words, you don’t want to get behind the wheel of a car for 8 hours after first trying your new fiber supplement.  You also don’t want to be dehydrated when taking a fiber supplement or you could even get stool impaction.  

Fiber can make things much worse by amplifying constipation or gut pain. 

Choosing the wrong fiber supplement type for you can also be extremely uncomfortable and even downright painful due to gas pain.  

So please, start slowly, choose carefully, be patient and open to trying different fiber types, stay hydrated and active, and be open to trying different types of fiber if one doesn’t work well for you. 

What is IBS-D?

IBS-D (irritable bowel syndrome-diarrhea predominant) is a type of IBS that is one of the functional gastrointestinal disorders.  This condition plagues people with diarrhea and abdominal pain, with the absence of any known physical causes.  

However, sometimes people with IBS-D can also have bouts of constipation as well. 

If you have diarrhea 25 percent of the time or more, with hard stools less than 25% of the time, you may have IBS-D.  

Of course, it is always important to get a proper diagnosis from your doctor or healthcare provider. 

An important point to understand is that IBS is often rooted in other health issues, diet imbalances, a poor microbiome, inflammation, and more.  This means that finding the root cause of IBS is the best way to help your IBS symptoms. 

Don’t despair: it can often be as simple as making an individualized meal plan based on how you respond to foods. 

Recovery from IBS

At least 25 percent of children who have IBS go on to have IBS as adults and most children who struggle with IBS have symptoms for greater than 5 years. 

The reasons for this could be many but often result from challenges getting children and adults alike to follow treatment recommendations for fiber and other lifestyle tips. 

You should know that eliminating food intolerances, adding probiotics, decreasing stress, trying digestive enzymes, and replacing natural vitamins can be very helpful for people struggling with IBS-D. 

Fiber is considered a very effective part of managing IBS for childhood and adult IBS symptoms according to research. 

Hint: you probably need to do more than just add fiber to manage IBS-D. But, as you can see, it can be an important part of managing this condition. 

You will need to know more about fiber, though, to get the most benefit from it.  

Why fiber TYPE is important

This is a big thing: people are not likely to continue a fiber supplement if it causes more side effects than benefits.  

Some types of fiber will leave you with more diarrhea, gut pain, and bloating. 

It’s not your fault; it’s just not the right fiber for you.  

This is why being picky about the kind of fiber you choose is important. 

For example, choosing a wheat dextrin fiber supplement, or other insoluble fiber would be a very POOR choice for IBS-D. 

Better choices would be acacia fiber, guar gum, beta-glucan, or psyllium fiber. I’ll get into why that is true. 

There’s more to the story than soluble and insoluble fiber

Soluble fibers are types of fibers that absorb water in the gut, making bowel movements more solid.  This is the primary reason why soluble fibers are better choices for IBS-D than insoluble ones.  

Insoluble fiber doesn’t absorb water and it can speed up intestinal movements, meaning that these types of fibers could make IBS-D worse.

But, not all soluble fibers are suitable for everyone with IBS-D either.  

For example, flaxseed is a great source of soluble fiber, but it can strongly increase abdominal pain for some people (not all people, but start slow to be safe).  

Flaxseed fiber may also be better tolerated with digestive enzymes or when it is fermented.  If your flaxseed supplement doesn’t have these features, I recommend using a different kind of fiber for the best results.

Also, if you have IBS-D because you have SIBO or small intestinal bacterial overgrowth, you may want to keep your fibers low FODMAP for a short period of time. 

While psyllium is a great fiber for many people with IBS-D, I have known some people who simply can’t tolerate psyllium, at least until they fully get a gut-healing diet in place. 

Best types of fiber for IBS-D

My first choices of fiber for IBS-D are acacia fiber, followed by guar gum, beta-glucan, and psyllium.  

Some people also do great with chicory, but this one needs a slow introduction for many because it can ramp up gas and bloat. 

Let’s dig in a little deeper about why these fiber types are the best options. 

Acacia fiber

Acacia fiber, also known as gum Arabic, comes from the acacia tree that grows in Africa and parts of Asia.  

This type of fiber has an abundant amount of soluble fiber and is well-tolerated by most people according to research. 

In a research study of people with IBS, using acacia fiber was especially helpful for people with IBS-D in controlling bowel habits when it was combined with probiotic yogurt compared to yogurt alone. 

Not only is acacia good for IBS, but it also helps reduce food cravings and hunger while also helping manage blood glucose levels. 

Improvements in bowel frequency and reduced gas and bloating are other positive effects seen from acacia fiber in a study of people who received 20 grams of acacia compared to a placebo. 

Yet another reason that acacia fiber helps with IBS is that it is a good prebiotic.  This means that it helps the body fuel a healthy bacterial content in the gut known as the microbiome. 

Three of the best fiber supplements for IBS-D contain acacia.  They are:

  • Heather’s Tummy Fiber Organic Acacia Senegal for IBS which is an unflavored, all-natural acacia fiber powder.  It is gentle on the stomach for most people. Of note, it’s best to use a shaker bottle when blending this fiber with liquid. 
  • Garden of Life Dr. Formulated Organic Fiber Supplement citrus-flavored all-natural fiber powder made with Organic Acacia, Organic Orange Peel, Organic Baobab Fruit, Organic Apple Peel, and Organic Cranberry Fruit.  I love this blend because it contains a variety of types of fibers, is easy to digest, and has a tasty, natural flavor. And, unlike Metamucil, there are no artificial ingredients or sweeteners. 
  • Acacia Fiber by Superdosing-this is a great organic acacia capsule for sensitive stomachs.  It is the perfect option for people who don’t want to mess with mixing fiber up every day. Just make sure to take this with plenty of water since you aren’t actually mixing it up with water. 

Guar gum

Guar gum is a type of fiber that comes from guar bean seeds. These seeds are a member of the pea family.  The fiber is usually sold as a partially hydrolyzed form in supplements.  

Highly soluble in water, guar gum literally soaks up water in the gut, which is part of why it is beneficial for people with IBS-diarrhea type. 

Research shows that people struggling with IBS-D have less diarrhea and also improved their microbiome when given partially hydrolyzed guar gum at 5 grams per day over a period of 4 weeks compared to a placebo. 

The other reason guar gum is great for IBS-D is that it doesn’t seem to come with side effects, at least according to a study of 60 children with IBS or chronic abdominal pain.  

What is more, children getting guar gum tended to have less abdominal pain and helped normalize bowel habits compared to a placebo. 

The best guar gum fiber supplement for IBS-D is:

Regular Girl, which is an organic powder, and is also a great prebiotic.  It contains Sunfiber Guar Fiber and Bifidobacterium lactis as a probiotic too. Also good for men.


Psyllium husk is the most popular fiber supplement and has been around as a supplement for the longest of all fiber supplements.  For this reason, there is more research evaluating its use for various digestive conditions. 

All studies that examine the effects of psyllium on IBS have resulted in positive benefits, especially in reducing the frequency of abdominal pain, even in children

According to Medical News Today, psyllium fiber helps with several kinds of diarrhea too, including those caused by the medication lactulose and diarrhea caused by cancer treatment. 

Like other soluble fibers, psyllium seed helps to soak up water in the gut, which reduces diarrhea symptoms in conditions like IBS.  It also has prebiotic effects, so its effects are synergistic in the gut. 

However, I have personally known a few people who simply can’t tolerate this fiber, but I suspect they needed to heal their gut first before trying it. So, don’t count it out, just make sure to start slow and get on a healthy diet regimen. 

A good psyllium supplement brand is:

  • Now Brand Psyllium Husk capsules– With over 5,000 positive reviews, this one is hard to beat. It is also a great way to buy a low dose of fiber for people who are new to fiber supplements. 


Beta-glucan is a type of fiber that is primarily found in oats, mushrooms, and barley. This type of fiber’s claim to fame is that it helps improve immune function and may even reduce cancer risk.  

Less research is available about the effects of beta-glucan on IBS, but one study did find that a combination of beta-glucan, inositol, and digestive enzymes had the ability to reduce bloating, flatulence, and abdominal pain in people with IBS.  

However, it makes sense that beta-glucan would have similar effects as other soluble fibers on the diarrhea symptoms of IBS-D because they have similar prebiotic fiber effects. 

The best choice of beta-glucan fiber supplement for IBS-D is Medicinal Mushrooms.

Fibers to use with caution

Even though some fibrous foods have a lot of soluble fiber, they can have some tendencies to increase gut pain and discomfort.  

The exact reasons aren’t known, but here are a couple of fiber foods to try cautiously. 


Both from personal experience and reviewer comments, I tend to avoid supplements of chicory (inulin) because they are more likely to cause abdominal bloating and gas, which can make people feel uncomfortable.  

Perhaps, if you stick with it longer, these symptoms will subside, but when you have gentler options like acacia, guar gum, beta-glucan, and psyllium, I’d start there first. 

That said, if you want to take fiber in a gummy option, chicory is the way to go.  The best chicory fiber supplement for IBS-D is:

  • Viteey Fiber Prebiotic Sugar Free Gummies-prebiotic chicory fiber in gummy form which is great for people who don’t like powders or capsules.  The other reason that this one is the best fiber gummy supplement is that it doesn’t contain any added sugars or artificial ingredients. 

Flax seed

Flaxseeds are a great source of fiber, but many people I have known who try it get a gut ache when eating them.  

For this reason, I highly recommend fermenting flax seeds first. Simply grind the flaxseeds, add water in equal proportions, and add a tablespoon of apple cider to the mix.  Cover and allow to sit for at least 4 hours at room temperature. 

In this way, the fibers become easier to tolerate by the gut due to a decrease in anti-nutrients, while also getting a good dose of probiotics. 

Related post: 11 Best Fiber Bars of 2022 + Organic and Low Sugar | (

Fibers to avoid with IBS-D

Some soluble fiber supplements are better to avoid altogether.  Here are a couple I suggest avoiding. 

Wheat dextrin

Wheat dextrin (Benefiber), a highly processed fiber, is a partially synthetic form of the carbohydrate portion of wheat that is processed to form a type of fiber.  

Many people who have an intolerance of wheat are actually intolerant of the carbohydrate part of the grain [R].  

For this reason, it is best to steer clear of wheat dextrin or wheat bran if you have IBS-D. 


Methylcellulose (Citrucel) is a synthetic form of fiber.  

Why would you choose a synthetic form when there are lots of natural forms out there?

Verdict: skip this type of fiber if you can reasonably find natural fibers. 

Low FODMAP fibers for IBS-D?

Low FODMAP foods and diets provide relief for many people who struggle with IBS according to research, but the long-term effects really aren’t known.  

Additionally, some “green-light” low FODMAP foods can be exceptionally irritating to some people’s IBS, such as flax or popcorn. This is one of the reasons why I have a hard time endorsing a low FODMAP meal plan for all people with IBS.

While the value of a low FODMAP diet for some people can be felt immediately, it should not be considered a long-term solution to IBS-D either because it may reduce the health of your microbiome.  

Still, it is a good idea to incorporate some low FODMAP dietary fibers in your diet if you have IBS-D.  

These fiber-rich foods include: 

  • Hulled pumpkin seeds
  • Chia seeds (preferably fermented)
  • Sweet potatoes
  • Nuts, preferably sprouted
  • Quinoa (preferably fermented)
  • Soaked and sprouted black beans (don’t skip the soaking and the sprouting)
  • Gluten-free oats
  • Oranges
  • Strawberries
  • Carrots

Remember, nothing takes the place of an individualized diet plan and listening to your body.  Seeking the help of a registered dietitian who specializes in function nutrition is your best bet to find the best approach for you. 

Related post: Milk Thistle for IBS, Liver Health, and More | The Healthy RD

Is a gluten-free diet better than a low FODMAP diet?

Research shows that simply following a gluten-free diet helps manage IBS-D symptoms in 71 percent of patients suffering from the condition. 

It is also much more straightforward than a low FODMAP diet, so this may be a better place to start for treating IBS-D or other functional gastrointestinal disorders than a complicated FODMAP food plan. 

How much fiber do you need per day? 

Most people undoubtedly get too little fiber in their diet daily. A good general goal for fiber per day is 25 grams for women and 35 grams for men.  

For the best health, you already know that the type of fiber you get really matters too.  Having a variety of dietary fibers from foods is important.

While the bulk of fiber you get in your day should be from healthy foods, a supplement can help fill in the gaps for many people with IBS-D. 

Related post: Helpful Supplements for Sugar Cravings

Fiber with probiotics may work better than fiber alone

Fiber helps support a healthy microbiome, so it makes sense that adding probiotics with fiber may be better than fiber alone for IBS.

Research shows that combining fiber with probiotics works better than prebiotic fiber alone for children with IBS.  

In fact, combining inulin fiber with the probiotic Bifidobacterium lactis was over twice as effective as the fiber alone. 

A good choice of fiber with probiotics is Regular Girl. It contains 5 grams of guar gum fiber per serving with 8 billion CFU of B. lactis. 

The information on this website is not intended as medical advice.  Consult your doctor or healthcare provider before making changes to your supplement regimen or lifestyle.

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