Tell us about your symptoms and treatment experience. Take our survey here.

one side of an avocado is an angel the other side is a devil

Fiber and IBD: Friend or Foe?

Understanding diet and IBD can be a bit of a minefield at times. Some days you can eat anything you fancy and other times you only have to take a bite of one of your triggers and you can end up spending the entire evening in the bathroom! One of the things many of us find tricky is the 'f' word: fibre! Yes, we know its good for us but if that's the case, why does it sometimes make us feel so bad? Let's chat about the benefits and pitfalls of fiber when it comes to life with IBD...

The negatives of eating fiber

There's a reason why fiber-rich foods are promoted as healthy; they help with all sorts of things such as lowering risk of heart disease and diabetes1 What's more, fiber is famed for keep things moving in our bowels and helping ease constipation. However, I'm sure you'll nod along with me when I say lots of do NOT need any help in that department!

Because of this, those with blockages or in the midst of a flare are often recommended a low residue diet; which limits the amount of fat and fiber consumed. The NHS states: "temporarily eating a low-residue or low-fiber diet can sometimes help improve symptoms of ulcerative colitis during a flare-up. These diets are designed to reduce the amount and frequency of the stools you pass."2 In other words, limiting fiber, in theory, can give your gut a bit of a rest and limit how often you go to the toilet.

Insoluble fiber, which is found in foods like leafy greens, bran, celery, and seeds, is known for effectively 'sweeping' through the bowel. The problem is some of us-myself included-can find these foods too tough to break and they can irritate our guts; leading to stomach ache and diarrhea. You only have to look at how tough the outside of celery looks to see it would be pretty tough to break it down and sometimes our tender digestive tract isn't up to the job!

The benefits of fiber

If what we've read is true, you might think cutting out fiber altogether is the solution to a happier gut. But actually, you'd be wrong. Fiber does have some benefits to those of us with IBD too. Firstly, it's important to note that the low residue diet is only recommended when you're flaring for short periods of time; it doesn't necessarily mean it'll help in the long term when you're in remission. For example, a study compared those with Crohn's on a low residue diet compared to those on a regular diet and found "there was no difference in outcome between the two groups, including symptoms, need for hospitalization, need for surgery, new complications, nutritional status, or postoperative disease recurrence.”

In other words, low residue might be a short-term fix but sadly the studies show it isn't a permanent solution. Whilst fiber can cause issues, it's also something we need for a healthy digestive tract and good gut bacteria. Fiber lowers the risk of colon cancer and a thriving gut bacteria can reduce symptoms of bloating and IBS. The study went on to explain that patients who ate close to 23.7g per day of fiber were actually 40% less likely to flare after six months; compared to those who only ate 10.4g a day. When we're not in a flare, it seems we DO need fibre and it can even help prevent the next one.

Types of fiber

It can be worth thinking about the TYPE of fiber we eat too. When I realized salads were a big no-no, I assumed that this extended to other types of fruit and veg too. But I then learned about soluble fiber. Soluble fiber is different from insoluble fiber which I talked about above and is found in things like oats, bananas, peeled apples, and Psyllium Husk. Unlike insoluble fiber, its a much gentler form and it's proven that it absorbs water in our digestive tract-meaning it can actually bulk up loose stools and diarrhea.

I find I do much better with soluble fiber: you only have to compare a mashed banana rich in soluble fiber to a tough leaf of celery (rich in insoluble fiber) to see how all types of fiber isn't the same! What's more, cooking and blending all helps break down the fiber in food-so perhaps it's worth trying a new strategy and ditching the raw salads for the cooked, blended veggie soups.

What works for me when it comes to fiber

As we can see, fiber is clearly a friend AND foe to those of us with Crohn's disease or ulcerative colitis. I'd love to hear how you find fiber with your disease but here are some tips I've personally found useful for myself.

  • If I'm having a tough day but still want to eat healthily, I'll blend everything and essentially have smoothies and soups. Nut butter is another example-it's much easier for me to eat a teaspoon of that than a handful of nuts! Juicing can go one step further-it removes most of the fiber but it is still a way for me to enjoy vegetables (like spinach and celery) which are just too tough any other way.
  • If I do have insoluble fiber, it's always in small quantities and I try to make sure I'll have soluble fiber in the same meal. For example, I might add a very small amount of seeds to porridge (oats are a source of soluble fiber).
  • I've found Psyllium Husk-a soluble fiber supplement useful in the past. The psyllium swells in water and forms a soothing gel-like consistency; which is thought to help bulk out loose stools. It's not like what you expect from a fiber supplement!
  • Whatever the fruit or veg, cooked is always better compared to raw for me. So even stewing apples rather than eating them whole can make a difference!

By providing your email address, you are agreeing to our privacy policy.

This article represents the opinions, thoughts, and experiences of the author; none of this content has been paid for by any advertiser. The team does not recommend or endorse any products or treatments discussed herein. Learn more about how we maintain editorial integrity here.

Join the conversation

Please read our rules before commenting.

Community Poll

How open are you about being diagnosed with IBD?