Can the Low FODMAP Diet Help with IBD?

The research on this is mixed. But many people with Crohn’s disease and ulcerative colitis report improved symptoms once they get the hang of this eating plan.

If you live with irritable bowel disease (IBD), then you may already know that there’s no one “IBD diet” that works for everyone. However, you may find that what you eat can affect your symptoms. So, you may try several different dietary approaches to manage your symptoms. One of these may be the low FODMAP diet.

FODMAP stands for fermentable oligosaccharides, disaccharides, monosaccharides, and polyols. Say that 10 times fast.

These are types of highly fermentable carbohydrates. When digested, they can create gas and chemicals that can lead to gastrointestinal (GI) symptoms.

You may have heard of the low FODMAP diet as an eating plan for people with irritable bowel syndrome (IBS). This plan was originally developed to help relieve IBS symptoms and can be effective at doing so.

However, IBD is very different from IBS, despite some overlapping symptoms. While the research on following the low FODMAP diet for IBD is inconclusive, some people find that it helps their symptoms.

However, the low FODMAP diet can be tricky to understand and follow. When I did the low FODMAP diet, it took me a while to get the hang of it. If you’re interested in trying it to help with IBD symptoms, read on for tips.

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How the low FODMAP diet works

The low FODMAP diet involves three phases:

1. elimination
2. reintroduction
3. personalization, sometimes called integration

In the first phase, you’ll remove all FODMAPS from your diet — don’t worry, this isn’t long term. In the second phase, you’ll reintroduce each FODMAP group in order to see what causes your symptoms.

In the final phase, you’ll eat normally but remove any FODMAP groups that brought on symptoms.

The evidence behind the low FODMAP diet for IBD

The International Organization for the Study of Inflammatory Bowel Diseases recommends a low FODMAP diet for people with IBD whose symptoms persist even after resolving inflammation associated with the condition and who don’t have strictures.

A 2020 systematic review analyzed data from 446 participants across 9 studies and found that the low FODMAP diet improved GI symptoms — specifically, abdominal pain, flatulence, and bloating — as well as fatigue and quality of life for people with IBD. However, it did not affect stool consistency or inflammation.

A small 2020 study compared the low FODMAP diet with a standard diet over the course of 4 weeks in 52 people with IBD. It found that those following the low FODMAP diet had more relief from gut symptoms (52%) compared with those on the standard diet (16%). Those following the low FODMAP diet also had a significant improvement in health-related quality of life.

The study found no significant difference between inflammation markers and microbiome diversity between the two groups.

You might wonder why the low FODMAP diet seems to ease IBD symptoms even though it doesn’t affect the inflammation caused by IBD. Some researchers argue that this could be due to co-occurring IBS and not necessarily due to IBD at all.

My personal experience

I embarked on the low FODMAP diet due to ongoing symptoms of chronic constipation, bloating, and abdominal pain. But it didn’t come naturally to me; I definitely had a learning curve.

For me, two parts of the low FODMAP diet were especially difficult. First was learning and identifying which foods contained which FODMAPs. Chances are, you also don’t innately know which foods contain monosaccharides versus polyols.

Second was feeling like my diet was very restricted during the elimination phase, especially during social events and holidays.

Thankfully, I had the help of a gastroenterologist and dietitian while navigating these hurdles.

After going through the elimination and reintroduction phase, I learned that FODMAPs aren’t a big trigger for me. I do get more bloated after eating fructans (think onion and garlic), which is a subgroup of oligosaccharides.

However, this is manageable for me because my bloating is not too severe. And now that I know fructans are a trigger, I can plan ahead and decide whether I want to consume them or not.

Overall, my worst symptoms remained the same and I moved on to a different treatment option.

My gastroenterologist did tell me that the low FODMAP diet tends to work better for people with diarrhea than those with constipation — and it can actually worsen constipation because it restricts fiber intake. So that could be why it wasn’t helpful for me.

Still, it was useful for me to rule out FODMAPs as contributing to my GI symptoms. Now, I have a lot of empathy for people who follow this diet. I also am more aware that onions and garlic, specifically, trigger bloating in me.

Tips for following the low FODMAP diet

Below are some of the tips I learned during the process, which may help you, too.

Work with a dietitian

My first piece of advice is to get all the help you can from medical professionals, particularly a dietitian trained in the low FODMAP diet. This can really make a difference when learning to follow this complicated diet.

Consider reading a book

As I’ve said, there’s a lot to learn when it comes to this diet, and I personally found that reading a book made the information easier to digest (pardon my pun).

“The IBS Elimination Diet and Cookbook” by Patsy Catsos, MS, RD, LD, was my favorite. It was easy to understand and included recipes. Although the title says “IBS,” it does mention Crohn’s disease and ulcerative colitis throughout.

Be mindful of portion sizes and food preparation

One of the trickiest parts of the low FODMAP diet is that portion sizes and food preparation can all influence FODMAP content.

For instance, a ripe banana is considered a high FODMAP food, whereas an unripe banana is low FODMAP.

A serving of five cherry tomatoes is low FODMAP, whereas a serving of nine is considered high FODMAP, so it’s recommended to spread servings out by a few hours or a full day.

Garlic is a high FODMAP food. However, garlic-infused oil is low FODMAP because of how it’s prepared. Boiling or canning some foods can also lower their FODMAP content.

Use an app

Another tool that helped me was an app recommended by my dietitian. I could quickly search for a food, and it would tell me whether it was a FODMAP or not, what type, and in what serving sizes.

This was the Monash FODMAP app, which was created by researchers at Monash University in Australia, where the low FODMAP diet was originally developed. It costs $8, but it made grocery shopping a lot easier.

Other smartphone apps include FODMAP Diet A to Z, Fast FODMAP, Fast FODMAP, and more. Check your favorite app store for others.

Eat more fiber

Many people have difficulty eating adequate amounts of fiber while on the low FODMAP diet, which can contribute to constipation.

Many of the foods you remove are fruits and vegetables, so it’s important to try to replace these with low FODMAP alternatives that you know you can tolerate. A dietitian can also help you find some alternatives.

Remember, this is a short-term diet

Finally, remember that the low FODMAP diet isn’t meant to be forever. The elimination phase lasts between 2 and 6 weeks, and reintroduction is around 6 to 8 weeks. In total, it shouldn’t take more than 4 months to settle on your personalized eating plan.

The takeaway

Many people know about the low FODMAP diet in relation to IBS, but some evidence suggests that it can be helpful for IBD symptoms, too, even though it hasn’t been shown to affect inflammation.

If you’re in IBD remission or have low disease activity but still have symptoms, you may want to talk with your gastroenterologist and dietitian about trying the low FODMAP diet. It’s a difficult diet to follow, but it’s short term and many tools out there can make the experience easier.