top of page
  • Tamar Feldman, RDN CDE


Updated: Jul 25, 2022

If you are an IBS patient, you were likely at some point or another handed a printout of the low FODMAP diet from your GI doctor or another healthcare professional. If you are like most individuals, the diet may have been so overwhelming that you either threw it in the trash or scheduled an appointment with a dietitian to plan it out practically. While the low FODMAP diet is a very useful tool that I utilize in IBS management, there are some significant misconceptions and limitations with it that patients need to understand.

FODMAP stands for fermentable oligo-, di-, mono-saccharides , and polyols. These are the scientific terms used to classify groups of carbohydrates that are notorious for triggering digestive symptoms like bloating, gas, and stomach pain. FODMAPs are found in a wide range of foods in varying amounts. Some foods contain just one type, while others contain several.

The main dietary sources of the four groups of FODMAPs include:

  • Oligosaccharides: Wheat, rye, legumes, and various fruits and vegetables, such as garlic and onions.

  • Disaccharides: Milk, yogurt, and soft cheese. Lactose is the main carb.

  • Monosaccharides: Various fruit including figs and mangoes, and sweeteners such as honey and agave nectar. Fructose is the main carb.

  • Polyols: Certain fruits and vegetables including cherries and nectarines, as well as some low-calorie sweeteners like those in sugar-free gum.

Both stomach pain and bloating in individuals with IBS have been shown to significantly decrease with a low-FODMAP diet. Evidence from four high-quality studies concluded that if you follow a low-FODMAP diet, your odds of improving stomach pain and bloating are 81% and 75% greater, respectively. Several other studies have suggested the diet can help manage flatulence, diarrhea, and constipation.

A low-FODMAP diet is more complex than you may think and involves three stages:

Stage 1: Restriction

This stage involves strict avoidance of all high-FODMAP foods. Many people are under the erroneous misconception that they are to avoid all FODMAPs long-term, but this stage should only last about 3–8 weeks, as it is important to include FODMAPs in the diet for gut health. Some people notice an improvement in symptoms in the first week, while others take the full eight weeks. Once you have adequate relief of your digestive symptoms, you can progress to the second stage.

Stage 2: Reintroduction

This stage involves systematically reintroducing high-FODMAP foods. The purpose of this is twofold:

  1. To identify which types of FODMAPs you tolerate. Few people are sensitive to all of them.

  2. To establish the amount of FODMAPs you can tolerate. This is known as your "threshold level."

In this step, you test specific foods one by one for three days each. It is recommended that you undertake this step with a trained dietitian who can guide you through the appropriate foods and methods of trial. Even if you can tolerate a certain high-FODMAP food, you must continue to restrict it until stage 3.

Stage 3: Personalization

This stage is also known as the "modified low-FODMAP diet." In other words, you still restrict some FODMAPs. However, the amount and type are tailored to your personal tolerance, identified in stage 2, allowing for more variety and flexibility. It is also important to remember that, unlike people with most food allergies, people with IBS can tolerate small amounts of FODMAPs.

My Take:

Although the low FODMAP diet is certainly effective in many cases, I prefer to utilize it as a short-term tool for up to 4-6 months maximum to reduce symptoms while treating the underlying root cause of IBS. Most FODMAPs are prebiotics, meaning they support the growth of good gut bacteria and are beneficial to the gut in the long term. In addition, many of the fruits and vegetables that are often necessary to be restricted on a low FODMAP plan are high in nutrients and antioxidants, making this diet, not an ideal long-term solution.

To schedule a nutrition consult with a gut-health trained Registered Dietitian expert, click here: or email

Tamar Feldman, RDN CDE is a Registered Dietitian/Nutritionist and a Certified Diabetes Educator, specializing in nutritional therapy for gut health, autoimmune disease, and hormone balance. She serves as the lead dietitian for GI Trak virtual gut health center and is a wellspring magazine contributor.

145 views0 comments


bottom of page