If you are struggling with digestive issues, you may already know how deeply gut issues impact your quality of life. Irritable Bowel Syndrome (IBS) is a common gut disorder that is classified by a range of symptoms such as abdominal pain, bloating, gas, constipation and / or diarrhea.

IBS affects between 7-15 percent of the worldwide population, although researchers believe that number to be higher, as many people with IBS do not seek medical support.

Do you think you have IBS?

If you think you have IBS, it is important to visit a doctor instead of trying to diagnose yourself. This is important as there can be other underlying conditions that can contribute to IBS-type symptoms but may be more serious. For example, there’s symptom overlap between IBS and Celiac disease, Irritable Bowel Disease (like Crohn’s disease or Ulcerative Colitis), gastritis, endometriosis and even gynecological cancers. Your physician can help you rule out more serious underlying conditions that may be impacting your digestion.

This is the Rome IV diagnostic criteria that physicians use to diagnose IBS:

“Recurrent abdominal pain on average at least 1 day/week in the last 3 months, associated with two or more of the following criteria:

Related to defecation
Associated with a change in the frequency of stool
Associated with a change in the form (appearance) of stool”

Already been diagnosed with IBS?

If you have either recently been diagnosed with IBS or have been living with it for a while, you may or may not have received information on how to manage your digestive issues. Some patients walk out of their doctors office with a prescription for laxatives or stool softeners without much other guidance on how to manage their new diagnosis.

Many of my digestion clients have been needlessly suffering for years without adequate symptom control. Unfortunately physicians do not normally address nutrition strategies for IBS, which are the foundation for better digestion and symptom control and management. Below I have outlined 3 fantastic diets to follow for IBS.

Please note that this article is for informational purposes only - if you are going to be excluding major food groups like the ones mentioned below, I recommend working with a dietitian (like yours truly!) to make sure:

You are getting enough nutrients
You are not compromising your microbiome - this can happen if you follow some of the below diets long term
You are creating a healthy and well balanced relationship with food.

A “SIMPLE” ELIMINATION DIET

An elimination diet is a generalized term for any diet that eliminates specific foods or food groups and then systematically reintroduces them to identify which foods are causing your symptoms.

The most common IBS triggers are:

Wheat
Dairy
Legumes
Added sugars
Caffeine
Alcohol
Fried foods

The foods you choose to eliminate on a simplified elimination diet depends on what your current diet looks like, what your symptoms are and what type of lifestyle you lead. For example, if you are eating a typical US diet (french fries, burgers, sandwiches, etc), you will probably benefit from eliminating wheat and dairy. But if you already avoid wheat and dairy and consider your diet to be ‘clean’ and plant based, you may benefit more from one of the diets outlined below.

THE LOW FODMAP DIET

The low FODMAP diet is the most research based diet for IBS. It was researched and created by Monash University in Australia.

FODMAP is an acronym that stands for Fermentable Oligo-Di-Monosaccharides and Polyols (wow! I know it’s a mouthful. Try saying it five times fast 🤪).

These are all just fancy / scientific names for fermentable carbohydrates that our bodies cannot digest or absorb. As a result, bacteria in the intestines ferment these compounds which can lead to uncomfortable symptoms like gas and bloating.

The low FODMAP diet is a 3 phase diet, characterized by the following:

Phase 1: Remove all FODMAPs to achieve symptom relief and symptom control. See below for examples on high FODMAP foods.
Phase 2: Systematically re-introduce FODMAP families to measure symptom control or recurrence in relation to the diet
Phase 3: Customization and personalization of your long term diet

Which foods do you eliminate on the low FODMAP diet?

FODMAPs are found in the following places:

Excess fructose (fruit sugar) – found in fruit, high fructose corn syrup, honey, and agave syrup
Lactose (milk sugar) -- found in milk, yogurt, ice cream and cheese (all dairy milk - cow, sheep, goat)
Oligosaccharides such as fructans and galactans, which are found in:
- Onions, garlic, wheat, barley, beans and lentils
Polyols - that are found in stone fruits, avocado, and sugar alcohols / sweeteners like sorbitol, mannitol, erythritol, etc.

It is best to work with a dietitian familiar with the low FODMAP diet who can ensure nutritional adequacy and safety of completing such a diet. If you need more guidance, check out my coaching options here.

Can I do the low FODMAP diet by myself?

I do not recommend completing this diet by yourself. It is important to work with a dietitian in order to customize your low FODMAP diet for several reasons. Here’s why:

Reason #1: A dietitian can help you maintain a healthy relationship with food. The low FODMAP diet can be confusing and can make your head spin a little 🤯. If you embark on this process by yourself, it is very easy to fall into unhealthy thought patterns about ‘good / bad’ foods or ‘healthy/unhealthy’ foods.

A dietitian trained in the low FODMAP diet can remove the frustrating guesswork and help you apply the low FODMAP diet efficiently and effectively, while managing food fears and promoting a healthy healthy relationship with food!

Reason #2: To make sure you’re getting the right nutrients. Whenever you remove major food groups from your diet, you are at higher risk for vitamin or mineral deficiencies. Working with a dietitian can ensure that you’re getting all the right nutrients.

Reason #3: To keep your microbiome happy! Research has shown that the low FODMAP diet can negatively impact your microbiome (the bacteria that live inside of your gut). This is exactly why the low FODMAP diet is not meant to be followed long term. FODMAPs are high in fibers known as prebiotics, which feed gut bacteria and promote a healthy microbiome.

The end goal is to have the least amount of restrictions and liberate your diet as your symptoms allow. A diverse diet = a diverse microbiome and a happy gut!

LEAP ELIMINATION DIET

Testing for your individual food sensitivities is another route for improving your digestive health. LEAP stands for “Lifestyle Eating and Performance” and includes a five phase eating plan that is based on your specific food sensitivities.

This is especially helpful for individuals who are specifically suffering from IBS-D (diarrhea) along with other inflammatory symptoms or conditions. For example, you are a good candidate for LEAP if you suffer from IBS-D and also have chronic pain, migraines or an autoimmune condition.

Think you might have a food sensitivity? Here’s a post that reviews the most common signs and conditions associated with food sensitivities.

Here is a sample food sensitivity report:

How does food sensitivity testing work?

You complete a blood test that measures your body’s reaction to 170 foods and chemicals (see a sample report above).
Once you receive your results, you can work with a dietitian to create a 5 phase nutrition plan where you initially limit your diet to the least reactive foods and gradually expand your diet over the course of 3-6 (or more) months.

Non-Diet Considerations in IBS

Nutrition is the foundation for optimizing digestive health. However, there are many factors beyond food that can also impact digestion.

Many functional gut disorders like IBS, constipation and diarrhea may require additional support beyond just food.

Here are some examples of non-diet factors that may impact digestion and IBS:

Inadequate digestive factors - your digestion is a cascade of acid, enzymes and bile that help your body break down food components so your body can absorb its nutrients. Without adequate digestive factors, you may experience digestive distress reflux, burping, gas, bloating, diarrhea, stools that float that do not improve solely with diet.

Microbiome factors - such as an infection (ex: C.Diff or E Coli) or a bacterial overgrowth like SIBO can contribute to IBS-type symptoms, which is why it is important to work with a physician. You may be at higher risk for a bacterial balance if you frequently use antibiotics or if you have recently experienced traveler’s diarrhea or food poisoning.
Stress levels - the brain and gut are so intricately connected, that stress, anxiety and depression can impact digestion and visa versa.

In functional medicine we are looking to identify and resolve the root cause imbalances that are contributing to your pain and discomfort. Sometimes there is more than one underlying cause, which is why working with a practitioner can also help you understand the wider picture on how to support your gut health with food and beyond.