3 Reasons Why the FODMAP Diet Isn’t Working (and what you can do about it!)

3 Reasons Why the FODMAP Diet Isn’t Working (and what you can do about it!)

If the fodmap diet isn't working the way you’d hoped, don't beat yourself up. There are 3 key areas to c heck in on in order to get YOUR best results from the FODMAP Diet. Click through to read the full article! #calmbellykitchen #ibs #fodmap

IBS symptoms can be numerous, varied, and hard to pin down sometimes. And when it comes to the treatment and management of symptoms, every person is a little bit different. 

People begin the FODMAP diet with the goal of treating a variety of symptoms and conditions. Because our bodies and our needs are different, it follows that each person will respond differently too.

While the FODMAP diet can be an absolutely life-changing decision for many people, not everyone has the same experience. 

After eliminating FODMAPs for six to eight weeks, you might feel amazing… or not. While a recent review of the research to date shows that 86% of people with IBS experience significant improvement in symptoms on the FODMAP diet, that might not be true for your experience so far. 

A Variety of Factors Affect Digestive Health

If it’s not working for you the way you’d hoped, we can still figure out what’s going on. In many cases, a few small tweaks are all you need to see a big difference.

But first, some reassurance: The majority of people don’t have 100% symptom improvement on the FODMAP diet. This is because food isn’t the only factor that affects your gut on any given day. 

(So if you were beating yourself up about slipping up, missing a sneaky FODMAP, or accidentally sabotaging yourself, I give you permission right now to stop doing that.) 

My goal is to make people feel better. And better is a process. 

Let’s try and figure this out, shall we? 

Check-in #1: Food Choices

Let’s start by gathering a baseline. Are you feeling some improvement with your symptoms? Think back to where you were before you started. Has anything changed? 

If your symptoms are around 70% improved, or better, then you’ve confirmed that FODMAPs play a major role in your digestive symptoms. To continue to see improvement, make sure that you are avoiding high-FODMAP foods and really sticking to your low-FODMAP plan in as many situations as possible. 

If your symptoms have improved somewhat—between around 30% and 70%—your quality of life has increased, but perhaps there’s more room for improvement. You're definitely on the right track (congrats!), so let's dig a little deeper.

What else might be going on? 

There are a few possible reasons why you didn’t experience a greater reduction in bloating, gas, diarrhea and constipation. I’ll discuss some other reasons why later in this post, but when it comes to your FODMAP intake, it's important to double check your adherence to the diet.

Make sure that you are compliant with the FODMAP diet the majority of the time. (By compliant, we mean your food choices AND serving sizes were on point according to the Monash FODMAP app.) 

Read the ingredient labels on any foods, as well as medications and supplements, you may take regularly. If you don't know what an ingredient is, google it to learn if it might be high in FODMAPs.

If you might not have been as compliant with the diet guidelines in the past, stick with the elimination phase for two to four weeks more. Don’t give up hope! There’s a good chance your symptoms WILL improve, with some small adjustments. 

If you were compliant with the diet guidelines, then it’s possible that a non-FODMAP factor could be causing problems. 

Keep on reading to learn more about the habits and lifestyle changes that might make an even bigger difference. 

If you’re not seeing any improvement in symptoms at all, follow the advice above to make sure you’ve removed all high-FODMAP foods and serving sizes from your diet. If you aren’t straying from the diet, then move onto Check-In #2.

>>> We made a helpful graphic to highlight the key takeaways from this article. Click to view the full size image, and click here to save it Pinterest. When you pin our images it also helps others find our articles and information--thank you!

Save the full image on Pinterest!

Check-in #2: Your Habits + Lifestyle

Changing your diet isn’t just about changing what you eat. There’s a lifestyle change, too. And that’s just as important. 

During the elimination phase, it’s common to identify other non-FODMAP factors that play a role in how your belly feels.

If you’re not seeing the improvement you wish in your symptoms from the FODMAP diet alone, consider the following:


Were your stress levels high for a good portion of the time that you were eliminating FODMAPs? 

Even if your diet was on point, your symptoms may have been aggravated by stress. Yes, it CAN make this big of a difference. 

Spend a week or two testing out stress management techniques. Adopt the ones that work for you and continue the elimination phase for another two to four  weeks. There’s a good chance your symptoms WILL improve. After that, continue on to the reintroduction phase.

Menstrual Cycle

Many women with IBS report that hormonal fluctuations throughout the month directly affect their symptoms. Consider keeping track of your symptoms and your cycle, and note if there are any correlations. Aim to eat comforting, familiar meals at the times of the month when your belly is most sensitive.

Also, if you’re heading towards menopause, there is some indication that IBS symptoms can worsen as hormone levels change and taper off in preparation for menopause. Listen to your body, and consider if these non-FODMAP factors might be causing you additional discomfort.


Healthy sleep habits are good for everyone, not just for your IBS! If you’re not getting enough solid, restful, and consistent sleep every night, then your body will probably be unhappy with you. Consider keeping a sleep log and noting down any times when IBS symptoms flare up. Is there a connection to your sleep? What do you observe?


Like sleep, keeping our bodies moving is essential to our overall well being. As I’ve mentioned in prior articles, incorporating movement and exercise can be a great way to reduce the severity of your IBS symptoms, in addition to the low-FODMAP diet.  

Quantity + Timing of Meals

Even low-FODMAP foods can exacerbate your symptoms, if eaten too quickly, or in too large a quantity. If you struggle with eating large portions and feeling stuffed, try eating smaller meals more frequently.

Non-FODMAP Problem Foods 

Carbonated drinks, alcoholic beverages, raw produce, high-sugar foods, or a high quantity of processed foods can all trigger your IBS symptoms, depending on how your body reacts. Keeping a food log is a great way to spot these non-FODMAP food issues.

Try new strategies one by one until you find what works for you. If you discovered other factors that negatively affect you, have you learned ways to manage and improve them? (You DO NOT need to be perfect—It’s the awareness that’s most important!)  

Once you've learned ways to manage these other factors (give it no more than two to four weeks—remember, you're not after perfection), you'll likely see more symptom improvement. Then it's time to move on to the reintroduction phase.

But if you think there might be other factors yet, or if the low-FODMAP diet just isn’t helping you at all, it’s time to consider other health issues with Check-In #3.

Check-in #3: Non-IBS Health Issues

You may be one of the people with IBS who don’t respond to the FODMAP diet at all. However, it may still be worth it to proceed with the FODMAP diet for two to four more weeks, then move forward with the reintroduction phase. By testing your tolerance to each FODMAP category individually, you’ll be able to determine the ones that have the greatest negative impact on your symptoms. You can avoid those foods, and not worry so much about the ones that don’t make a big difference. 

If the FODMAP diet didn’t help you like you thought it would, there may be a condition or other underlying factor, either instead of, or in addition to, IBS.

I encourage you to seek out a doctor to explore other treatments. Traditional doctors aren't the only option. Explore functional medicine doctors, naturopaths, or dietitians. Ask about his or her experience and philosophy around treating digestive disorders.

Could it be SIBO?

One of the common conditions that’s misdiagnosed as IBS is SIBO, which stands for Small Intestine Bacterial Overgrowth. It’s a treatable condition, and your GI doctor can do a breath test to check to see if you have it. People with SIBO experience many similar symptoms to IBS, and one common sign is that most meals cause bloating soon after eating. 

The FODMAP diet can help your symptoms, but you need to be treated specifically for SIBO to see a big improvement. If you have SIBO, a modified FODMAP Diet is often needed, together with antibiotics, so consider getting expert help. 

Non-IBS Health Concerns

The FODMAP diet is sometimes recommended for other digestive issues besides IBS. However, there isn’t a lot of research to help us gauge just how much of an impact the FODMAP diet can have on these non-IBS conditions. 

If you experienced noticeable symptom improvement, that shows the FODMAP Diet is indeed helping your condition—this is good news. You might consider continuing the elimination phase for two to four additional weeks, paying close attention to what you eat and how you feel. Change and adjust anything that's not working optimally, but keep in mind that your level of symptom improvement may have already reached its peak. 

On the other hand, if you felt negligible improvement in your symptoms, you might consider checking in with your doctor. Discuss your results, and ask what they recommend next for your specific situation.

If your head is spinning right now, don’t worry! It’s normal!

Your body is complex, which means there are a wide variety of things to consider when the FODMAP diet doesn’t immediately work.

Whatever you do, don’t lose hope. Like I said above, feeling better is a process. Go through this article again and make notes on what you want to focus on next in this health journey. 

Wish food shopping weren’t so time-consuming on FODMAP? Our free shopping list can help. Click to get it!