Fiber & IBS - Finding the Right Low-FODMAP Diet

Fiber and Irritable Bowel Syndrome (IBS) have a complicated relationship. In some cases, fiber can trigger IBS symptoms, and in others, it is recommended as a treatment. The reason for this complicated relationship is because not all fiber is created equally, and also because cases of IBS are highly individualized and highly personal to navigate.

But before we dive too deep into the relationship between fiber and digestive health, let’s start at the beginning: what IBS is and the most common ways it presents itself in people. 

What is Irritable Bowel Syndrome?

IBS is a common condition resulting from imbalances in our body’s large intestine. These imbalances can be the result of too strong or too intense muscle contractions (whereas normal contractions aid digestion), abnormalities in the nervous system, an excess of unhealthy bacteria, early life traumas, or changes to the gut microbiome (the colony of microbes living in our gut). 

When these intestinal imbalances occur, the process by which our bodies digest food is disrupted, causing uncomfortable symptoms for people at varying levels of severity.

Common IBS symptoms include:

• Abdominal pain and cramping 
• Irregularities in bowel movements and their rhythms
• Gas and bloating
• Food triggers
• Disrupted sleep
• Mood disorders

The frequency and severity of these symptoms vary from person to person, as do the things that trigger them. Because each case of IBS is so unique, there is no universal method for treating it. Working with a doctor to help you navigate your symptoms, triggers, and treatment is always the best practice.

How does Fiber affect IBS?

Because constipation is one of the most common ways IBS presents itself in people, fiber is often used to assist healthy bowel movements. But, here’s where things get a bit complicated. Sometimes, the same fiber source that helps alleviate constipation in one person could trigger uncomfortable symptoms of IBS in others.

To help explain how this is possible, we have to delineate between the two types of fiber, and how they interact with the digestive system: Insoluble and soluble fiber. 

Insoluble fiber, Soluble fiber, and IBS

Generally speaking, fiber adds mass to stool, helping it pass more effectively through our bodies. But, the way fiber adds this mass is dependent on the type of fiber it is. 

Soluble fiber, or fiber that is capable of dispersing in water, adds mass to stool by increasing the amount of water that stool is capable of absorbing. With increased water-holding capacity, stool is softer, and therefore, easier to pass. Soluble fiber can be found in foods like psyllium husks, oats, and flax, and often help improve stool consistency and bulk.

Insoluble fiber, or fiber not dispersible in water, adds mass to stool by increasing the amount of physical matter comprising it. This bulking process can help alleviate constipation in some people, but for those with certain IBS complications, it may trigger other forms of discomfort. Insoluble fiber is found in foods like wheat bran and the skins of fruits and vegetables and is often avoided or consumed carefully by people with IBS.

Low FODMAP Fiber and IBS

One of the most common ways people incorporate fiber into their diets while navigating IBS is to seek out low FODMAP sources of fiber.

FODMAP is an acronym for Fermentable Oligosaccharides, Disaccharides, Monosaccharides, and Polyols (which is why we’ll stick to calling it FODMAP). Put simply, FODMAPs are carbohydrates that are resistant to digestion, and consequently, can cause gas, bloating, and other digestive discomforts, especially for people with IBS.

Often, people with IBS reduce their intake of FODMAP foods, like apples, artichokes, wheat bread, and split peas, by adopting a low-FODMAP diet. But, low-FODMAP diets can make getting a healthy amount of fiber difficult. And, as we’ve established, the right kinds of fiber are important for digestion and can help alleviate some IBS symptoms.

So, finding sources of low-FODMAP, high-soluble fiber has the greatest potential to help people manage their IBS. Foods like kiwifruit, oatmeal, brown rice, chia seeds, and green beans can be complemented by fiber supplements like natura fiber.

Natura fiber is a good source of low FODMAP fiber, comprised of many soluble fiber sources like psyllium husk and flax, making it a great addition to the diets of many people navigating IBS.

If you think natura fiber could be a good fit for addressing some of your IBS symptoms, consult your doctor about adding it into your regular or specialized diet.