IBD Diet Myths Debunked by an IBD Dietitian: Part 2

Myth 1: “Diet Doesn’t Matter In IBD so I just eat what I want”

A: Not exactly.

The first question people often ask when diagnosed with IBD is, "Did my diet cause this?" But the answer is always no. What triggers IBD and other autoimmune conditions is complex and likely a combination of genetics, environment and the immune system. 

However, once you have a diagnosis, diet can play a huge role in managing IBD symptoms. We also need to ensure we are getting the right vitamins and minerals as the ability to absorb foods may be affected. 

Certain diets are now also used clinically in specific situations, as mentioned above.

Nutrition matters hugely, but it should always complement medical care, not replace it.

Myth 2: “People With IBD Should Avoid Fibre”

A: No, not forever.

This is probably the biggest myth I see in the clinic, and one I’ve experienced myself, also having Crohn’s Disease.

Like many people, I was given a low fibre diet sheet on diagnosis. Unfortunately, this wasn't followed up with regular support from a dietitian. So I never learnt how to transition away from this as my disease went between flare up to remission.

I now see this often in my own clinic, people with IBD who haven't eaten fruit, vegetables, pulses or wholegrains for years because they’re terrified of symptoms.

For many people with IBD, low fibre eating starts as a temporary strategy during symptoms or flares. But without specialist support, it can slowly become a long-term pattern. 

The current guidelines on following a Mediterranean-style eating pattern rich in plant foods, olive oil, fibre and minimally processed foods. 

Fibre is important because it:

• feeds beneficial gut bacteria
• supports production of short-chain fatty acids like butyrate
• helps maintain the gut lining
• supports bowel health overall

If you have been restricting fibre, your gut will need time to adapt to having more, so always gradually increase! You can modify texture and type first:

• cooked vegetables instead of raw
• smooth nut butter instead of whole nuts
• peeled fruit
• oats instead of bran cereal
• lentils in small amounts at first, rinsed thoroughly!

If you have strictures or narrowing in the bowel, fibre advice absolutely needs individualisation with your IBD team or Dietitian.

Myth 3: “Cut out all Gluten”

A: Not unless you also have coeliac disease too

Many people with IBD feel worse after eating bread, pasta or processed foods and assume gluten must be the culprit.

Some people do genuinely feel better when reducing gluten-containing foods. But often this is because:

• they’ve reduced highly processed foods overall
• they’re eating fewer fructans, a type of fermentable carbohydrate which can cause bloating and wind
• or they have overlapping IBS-type symptoms

That’s very different from gluten directly worsening inflammation, which is often claimed online. The unnecessary restriction of gluten can make your food shop more expensive and reduce your overall fibre intake.

If you suspect gluten is an issue:

• speak to your GP before removing it completely
• get tested for coeliac disease 
• consider whether IBS-type symptoms may also be present

Once you have ruled out Coeliac Disease, finding ways to reduce trigger foods that have fructans in them (without removing gluten completely) can be an easier strategy long term!

Myth 4: “You Should Cut Out Dairy”

A: Only if dairy genuinely affects you.

For many people, it’s not actually the dairy itself causing symptoms. It’s lactose, the natural sugar found in milk and some dairy products. 

Cutting out dairy is only recommended if there is a confirmed lactose intolerance (please speak with your GP or gastroenterologist for this).

Unnecessarily avoiding dairy can restrict lots of beneficial things like:

• Calcium
• Vitamin D
• Protein

All things which are important for bone health and overall energy!

It’s important to note that not all dairy has the same amount of lactose. So if you notice symptoms during a flare up, you may still tolerate dairy which has lower lactose in it. For example:

• yoghurt
• hard cheese
• lactose-free milk
• kefir

Myth 5: “Probiotics Will Fix My Gut”

A: The evidence is mixed and strain-specific.

This is where marketing has massively outpaced science.

The reality is that there is currently very little strong evidence that probiotics broadly improve CD outcomes.

Some specific probiotics may have a role in UC or pouchitis, but results are inconsistent and highly strain-dependent.

That means:

• not all probiotics do the same thing
• many haven’t been properly studied
• and more isn’t always better

In some cases, high-dose probiotics can actually worsen bloating and discomfort. So it’s better to save your money unless a Specialist Dietitian has recommended a specific product for a specific reason.

Myth 6: “If I’m In Remission, I Should Feel Completely Fine”

A: Not necessarily.

People often struggle to know what remission feels like because ongoing gut symptoms are so common. So if you have been told your tests are “normal”, but you're still: 

• bloated
• exhausted
• rushing to the loo
• scared to eat
• falling asleep at your desk
• cancelling plans because your gut feels unpredictable

Your symptoms are still real and could be linked to the following:

- Nutritional Deficiencies

People with IBD should have nutritional screening every year during remission. Taking weight and height during reviews is not enough!

Blood tests should be carried out to monitor nutrients such as iron, vitamin B12 and vitamin D. Assessing your diet is also important to ensure you are eating enough overall and getting key nutrients such as iron, vitamin C, calcium and fibre.

- IBS-like symptoms on top of IBD

Up to 35% of people in IBD remission can have IBS-like symptoms. This requires a completely different approach to managing IBD alone, like the low FODMAP diet as mentioned previously.

What is the most important thing to know?

Working with an IBD-Specialist Dietitian during a flare up is key to advising you on your specific situation.

During remission, the current evidence and guidance suggests:

• Eating as varied a diet as tolerated - aiming for a Mediterranean style diet
• Minimising intake of processed and red meat
• Including fibre in forms tolerated
• Still working with an IBD-Specialist Dietitian 

It’s likely your IBD diet will keep changing because IBD can fluctuate a lot! So knowing how to adapt your diet to what your body and disease are doing is incredibly important.  

And if you are looking for more information on IBD and Diet, go to crohnsandolitis.org.