Reacting to FODMAP challenges

Reacting to FODMAP challenges is an unfortunate but highly likely side-effect of the reintroduction phase. When it first happens to you it can feel like a failure. Read on to find out how to deal with it and what it means for you.

I'm scared to cause a flare-up

It's completely natural to be scared about risking a potential flare-up. Whilst it's all part of the process, when it does occur it's not a welcome result. Try to remember that you're in control and can stop the challenge at any time.

The purpose of gradually reintroducing foods is to reduce the likelihood of causing a huge unexpected flare-up. If you’re going to respond very badly to a particular FODMAP then these reactions will usually begin on days 1-2. This means the portion sizes are still relatively small so our reactions should typically be less severe. This then gives you the opportunity to decide if you want to continue with the challenge or wish to stop.

Generally, mild reactions are to be expected and tolerated by most people. Any time you experience an intolerable moderate to severe reaction you should stop and begin the 3 day washout period. This applies whichever day of the challenge you're on when it happens. You can then choose to attempt to reintroduce this FODMAP again in the future. For now, you'll consider the previous serving size to be your typical tolerance level.

What happens when reactions occur

It will usually be fairly obvious when you're reacting to a FODMAP challenge. Typically, your symptoms will begin to increase beyond the baseline you established in the elimination phase. They can vary from mild to severe reactions and may be over quickly or continue for several days. Let's look at how this works within your reintroduction schedule and how we can deal with it.

As an example let’s say you’re reintroducing sorbitol in the form of avocado:

Example 1 - Mild-moderate reaction

• Day 1 @ 40g: No symptoms. No discomfort. Happy to progress on to day 2.
• Day 2 @ 80g: Mild symptoms. Mild bloating. Mild discomfort. Progress on to day 3
• Day 3 @ 120g: Moderate symptoms. Severe bloating. Moderate discomfort.

Begin 3 day washout period and allow symptoms to return to baseline before attempting another FODMAP challenge. [1]

In this example, you would put your tolerance to sorbitol between a small to medium portion. This depends on the type and severity of symptoms you’re prepared to tolerate in your usual daily life.

You’ll continue to eat a low FODMAP diet for the duration of the rest of your challenges. You can start adding sorbitol containing foods back into your diet in small to medium portions in the personalised phase.

As another example let’s say I’m reintroducing sorbitol in the form of avocado:

Example 2 - Severe reaction

• Day 1 @ 40g: Moderate Symptoms. Moderate bloating. Moderate discomfort.

Stop challenge and begin the 3 day washout period.

In this example, I decided that as the smallest portion caused a moderate reaction I did not wish to continue to increase the portions. This helps me to avoid causing a severe flare-up. Given this result, I may consider this sorbitol reintroduction a fail. For now, I'll continue to limit sorbitol containing foods in my diet.

However, I may decide that because I love avocado I’ll only eat it in very small quantities. This is best done at times when a moderate reaction is less likely to affect my life. I'll also return to this sorbitol challenge in the future to see if and how my tolerance changes over time. This future rechallenging process of FODMAPs is very important. So many factors, other than purely the FODMAPs, can contribute to our gut health over time.

You decide how much is too much

Remember, when it comes to reacting to FODMAP challenges there are no definite markers. What constitutes moderate to severe reactions for each of us is subjective. These levels will be different for everyone and each of us gets to decide how much is too much.

You’re basically looking to keep your symptoms within the severity you are prepared to tolerate on an average day. This should be a level that causes minimal disruption to daily habits and your quality of life.

The reaction you’re prepared and able to tolerate may also change over time. This can be affected by your circumstances, food cravings and overall health. Many people find that during periods of relative "wellness" and relaxation they are better able to tolerate FODMAPs. For example, when away from the stress of daily life, say whilst on holiday, you may experience fewer flare-ups and gut issues. [2]

It’s important to keep in mind that in the case of IBS we're not causing physical damage to our bodies. This applies where no other allergies or inflammatory conditions (such as IBD) are present. This means you’re not risking your health or causing lasting structural changes to your digestive system by performing these challenges. [3]

The biggest risk to overall gut and general health comes with self-diagnosing IBS. The second biggest factor is overly restricting food and FODMAPs long term. This is what we’re attempting to minimise during a methodical, well-timed reintroduction phase under the guidance of a registered dietitian.

Are you looking for more support during your reintroduction phase? Check out the other posts in this series.

Which FODMAPs do you react to?