Managing IBS: What if the Low FODMAP Diet doesn’t work for you?
Are your IBS symptoms caused by other triggers?
If you have irritable bowel syndrome (IBS), you may have read about the low FODMAP diet.
Since 2006, research has shown that the FODMAP may be the #1 cause of the digestive symptoms of people living with the syndrome.

In fact, it is now recommended by the scientific community, when other more concerning diseases have been ruled out as described in this article previously posted on our blog, to initiate the low FODMAP diet in order to identify potential food triggers to digestive symptoms. However, there are others triggers to the symptoms of IBS and the FODMAP doesn’t always explain this all.
In this article, we will review the FODMAP diet as well as other common IBS triggers.
How the Low FODMAP Diet works
This diet consists of 3 phases in which the person living with IBS can identify one, or multiple, FODMAP families that trigger their symptoms. These FODMAP families are lactose, fructose, fructans, galacto-oligosaccharides (GOS), mannitol and sorbitol, which each contain several food items.
- Phase 1 (Elimination): This step requires the elimination of all food known to trigger symptoms. After a few weeks, typically 2-6 weeks, the person should feel better or be symptom-free. At this point, it is not yet known which family triggers symptoms (which is discovered in the second phase).
- Phase 2 (Reintroduction): This step is essential to identify which family triggers symptoms and how much can be tolerated. By methodically reintroducing one food item at a time, the symptoms will be monitored closely and the food triggers may be identified.
- Phase 3 (Personalization): This step consists in building the new lifestyle from what has been discovered in the second phase. Only the triggers will be eliminated or limited depending on the results from the reintroduction phase.

The most recent data from Monash University shows that about 75% of people with IBS respond to the low FODMAP diet. In other words, 25% of people don’t see their symptoms resolved after 6-8 weeks while being in phase 1. If this happens, it is important to stop the low FODMAP diet and to identify other potential IBS triggers.
What to do if the low FODMAP diet doesn’t work?
First of all, I would always advise anybody trying the low FODMAP diet on their own that does not see results after 6-8 weeks to consult with a FODMAP Trained Registered Dietitian. It is important to evaluate the compliance to the low FODMAP diet before it is ruled out. If the compliance is perfect and symptoms are still present at a high intensity, then it is important to consider other sources.
1. Stress
It is well known that stress is a very powerful trigger to IBS symptoms. This is what we call the brain-gut axis. In this 2019 article, Diana Reid, explains there is a close relationship between the symptoms and the brain. It says that “uncomfortable or embarrassing gut symptoms cause stress, which then triggers further painful symptoms. Or, the reverse is also true: the fear of encountering symptoms leads to the symptoms themselves roaring in.”
If there’s a feeling of stress, anxiety, being tired or having difficulty sleeping, then the digestive symptoms may worsen. In order to manage them, it is important to improve sleep and find some tools to destress, such as taking a bath, reading, folding some clothes, going for a walk, doing some yoga or meditation. Talking to a registered counsellor or psychologist is also often recommended and beneficial. A more recent research area of interest for the management of IBS is hypnotherapy. However, as explained in this study, the process is not yet fully understood.
2. Caffeine
Multiple studies have shown that the consumption of caffeine, mainly in the form of coffee, exacerbates the symptoms by 26-40%. Caffeine would have a laxative effect resulting in looser bowel movements.
Other sources of caffeine include green or black tea, milk or dark chocolate, energy drinks, some soda drinks (Root Beer, Cola) The good news: Decaffeinated coffee didn’t show an increase in symptoms in all studies!
3. Alcohol
No study has shown an impact of digestive symptoms and the consumption of alcohol, but Monash University has compiled enough observations and anecdotal evidence to make a recommendation. Alcohol acts as an irritant to the digestive tract resulting in altered digestive motility, permeability and absorption increasing the symptoms of IBS. The current recommendation from Monash University is to drink no more than 2 drinks a day (men or women).
4. Spicy foods
This may affect many people living with IBS or not. Capsaicin, a molecule found in hot peppers and responsible for the “hot” sensation, can increase the transit time of the food in the digestive tract, increase the sensitivity and cause a burning sensation on the inside.
It might be stressful, challenging and very overwhelming to identify the triggers of IBS symptoms. In order to feel better, it is important to consider the big picture and identify and limit stress associated with the process. If you are diagnosed with IBS or have digestive symptoms that impact your quality of life, don’t hesitate to communicate with us to see a FODMAP Trained Registered Dietitian.
Sign up for our Sound Bites newsletter to learn more nutrition tips and healthy recipes from our Registered Dietitians.
As university-trained Registered Dietitians, you can count on us for credible advice and practical meal planning so you don’t have to stress about food anymore. You can achieve a healthy and joyous relationship with food and your body.
You might also want to check out these previous articles on our blog:
Olivier is both detail oriented when it comes to solving complex health issues yet practical and personable in his approach to counseling his clients. As a vegetarian for over a decade and with family members that love meat, he always finds creative ways for families to be successful in diverse eating styles.Olivier specializes in Digestive Health, Vegetarian Diets, Weight Concerns, Chronic Disease (Heart, Liver & Kidney Disease, Diabetes), and Seniors Health