Part 3: IBS Series – Getting Started on the FODMAP Diet
Turn the FODMAP theory into practice
Part 3 of a 4 part series to get to the root of your digestive woes and explore the role of a low FODMAP diet in managing Irritable Bowel Syndrome. This blog post discusses how to start a low FODMAP diet.

In our previous articles in this IBS Series, we have seen what the FODMAPs are and what is the role of the low FODMAP diet in IBS management .
Now that we know what FODMAP means, where to find them and their potential role as digestive symptom triggers, let’s review how to start a low FODMAP diet through the 3 phases of the FODMAP protocol.
What to consider before initiating the 3-phased FODMAP protocol
It is important to keep a few things in mind before starting the low FODMAP diet.
First, the low FODMAP diet is intended to help manage the symptoms of a few digestive conditions such as the Irritable Bowel Syndrome (IBS) or the Small Intestinal Bacterial Overgrowth (SIBO). These conditions are syndromes and not diseases. It is very important to rule out diseases affecting the digestive tract otherwise you would undergo the FODMAP protocol with no success and may get sicker by not addressing the real issue. These diseases include but are not limited to Celiac Disease, Crohn’s Disease, Ulcerative Colitis, Diverticulitis, Gastroparesis.
Here are some tests and investigations you doctor may recommend you to do:
- TTG IgA for Celiac Disease (it is important to be on a gluten containing diet for this test)
- Small intestine biopsy
- Colonoscopy or endoscopy
- Abdominal Ultrasound
- Stool sample analysis
For more information about the tests and investigations for digestive issues, see this article from Monash University. If you haven’t done any of these tests, we strongly recommend to reach out to your doctor first before undergoing the low FODMAP protocol.
Other things to consider before starting the low FODMAP diet are your current obligations, lifestyle, cooking ability and plans. Keeping in mind that it is required to be on this very restrictive diet for a few months, did you consider:
- Planned vacations or trips that would prevent you from following the diet
- Obligations that prevent you from cooking your meals regularly
- Access to cooking equipment to make your own meals
If you are unsure if it is the right time to start the 3 phases of the FODMAP protocol, give us a call and speak to one of our Trained FODMAP Dietitians and Digestive Health Nutritionists.
How to complete a 3-phased FODMAP protocol
You’ve read us mentioning the 3 phases of the low FODMAP diet a few times already in these articles of this IBS series. Without further ado, here are the 3 phases of the FODMAP protocol to start and follow a FODMAP diet: Elimination, Reintroduction and Personalization.
Phase 1 – Elimination
The first step consists of eliminating all High FODMAP foods from the diet until the symptoms get better or fully disappear. It may take up to 6 weeks to feel better, even if a strict low FODMAP diet is being followed.
As previously seen, there are a lot of foods containing FODMAPs such as produce grains and cereals, nuts, legumes, lentils, dairy products and a variety of processed foods. This often makes things tricky to:
- Stick to the diet. Eating low FODMAP may seem blend and repetitive. However, there are many tips, resources and products that can be used to diversify your eating and flavor up the food.
- Have balanced meals. Sometimes it seems just easier to avoid eating completely a food group and to substitute by another one. Our advise: Keep your meals balanced. Lacking a food group may have negative impact on your digestion, as explained in our previously published article https://www.healthstandnutrition.com/soluble-vs-insoluble-fibre/ , causing more diarrhea or constipation, and then delay the relief of your symptoms AKA being on the low FODMAP diet for a longer period of time.
If there is a relief in the symptoms, you can now move onto the second phase. If after 6 weeks there are no changes in the symptoms, it is important to work with your dietitian to identify the causes and see what to do from there.
Phase 2 – Reintroduction
This step is essential to identify which one of the FODMAPs triggers symptoms and how much can be tolerated. By reintroducing methodically 1 food item at a time, the symptoms will be monitored closely and the food triggers may be identified. During this phase, that is typically completed in 6-8 weeks, it is important to remain on the low FODMAP diet except for the only food item being reintroduced.
To test the different categories, the Monash FODMAP App is a very useful tool, since it has pre established food items with amounts per families. You simply have to pick 1 food you want to reintroduce, start with the small amount (day 1) normally recommended at your 1st or 2nd meal and monitor your symptoms for the rest of the day. If you have no change in your symptoms you can increase to a medium amount (day 2) and so on. Keeping a journal of your symptoms, stress level and food eaten is important during the 2nd phase in order to catch potential false negative readings.
It may feel scary to move into the phase 2 because you have been feeling great since being on the first phase. However, it is important to consider that being on a strict low FODMAP diet is unsafe, because it increases the risk of several nutrient deficiencies, and restricts food categories that have no reason to be restricted since they don’t trigger symptoms. It just happens that you don’t know what triggers your symptoms yet.
Phase 3 – Personalization
This step consists in building the new lifestyle from what has been discovered in the second phase. A regular balanced diet can now be followed except the FODMAP category(ies) that have been identified to increase the digestive symptoms.
The intolerance to the trigger(s) identified is typically for life. However, IBS is a condition that evolves over time, which means that your tolerance may be better or worse over time. For this reason, it is recommended to test your intolerance about every 6 months.
Feeling overwhelmed and unsure what to do next?
Don’t go through this journey alone and reach out to one of our Trained FODMAP Dietitians and Gut Health Nutritionists for support to have all the keys to success!
Find the right Digestive Health Dietitan to tackle your IBS symptoms by contacting us today!
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Olivier Yergeau
Registered Dietitian
Olivier Yergeau is a Registered Dietitian in Prince George, British Columbia.