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How to Take Care of your IBS with Nutrition Basics

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When our team of registered dietitians hear clients’ stories of their Irritable Bowel Syndrome (IBS) there’s one thing all clients have in common: frustration. There is so much frustration about living in discomfort, dealing with IBS symptoms, being cautious of food choices, and worrying about embarrassing gas and urgent bowel movements in public. IBS and nutrition is confusing and frustrating!

Oftentimes, the frustration comes from having to follow strict diets such as the low FODMAP diet. While the low FODMAP diet has excellent evidence for helping IBS symptoms, it IS a restrictive diet. It is very confusing, and is often done incorrectly without dietitian support.

In reality, we often find that there are simpler places to start with IBS management, that aren’t so restrictive! As a GI dietitian and owner of Ignite Nutrition, I’m excited to talk to you today about where to begin with IBS and nutrition. Plus, we’ll review the comparable success rates of different dietary approaches to IBS management by looking at the evidence we have so far! In particular, we’ll review two alternatives to the low FODMAP diet that work well for IBS. These include the NICE dietary guidelines for IBS and the Mediterranean diet.

Table of Contents:

  1. What are the NICE guidelines for IBS?
  2. Adjusting Fibre Intake
  3. Increasing Fluid 
  4. Limiting Caffeine, Alcohol, and High Fat Foods
  5. Avoiding Sugar Alcohols & Limiting Fruit Intake
  6. Meal Spacing & Mindful Eating
  7. The Mediterranean Diet for IBS
  8. Other Dietary Considerations for IBS
  9. FAQs

Nutrition is one of the pillars of IBS management. As dietitians, it tends to be our favourite one to talk about. However, our goal for our patients isn’t to limit foods but instead to have your symptoms managed while being on the most liberal diet possible. One of the most common IBS management mistakes we see at Ignite is jumping right to food restrictions and elimination diets.

Dietary restrictions are just that – restrictive and complicated, particularly if you’re doing it on your own. When it comes to nutrition management of IBS, we often want to start with the basics of nutrition! This may seem like ‘common sense’. However, we find when we really tailor these recommendations to your needs – we may not need to use the low FODMAP diet or may just use pieces of the low FODMAP diet to complement the work you’ve done already.

What are the NICE Guidelines for IBS?

A UK-based body called the National Institute of Clinical Excellence (NICE) created guidelines back in 2008 around IBS management. These guidelines outline both dietary and lifestyle factors to assist with the management of IBS and are deemed to be a first line therapy option for patients prior to moving to a low FODMAP diet if necessary. As new evidence emerges, these guidelines continue to get reviewed and updated. 

What we LOVE about these recommendations is they’re a simple, food-first way to get started BEFORE seeing your dietitian, or if you’d prefer not to do a strict elimination diet. We always like to say that the low FODMAP diet should be implemented under supervision of a trained dietitian. Which is why starting with this is often safer, and can provide symptom relief!

NICE Guidelines for IBS at a Glance

  1. Adjust fibre intake
  2. Increase fluid
  3. Limit caffeine
  4. Limit alcohol and carbonated drinks
  5. Limit fat intake
  6. Avoid sugar alcohols
  7. Limit all fresh fruit to 3 portions per day
  8. Have regular meals

Let’s dive deeper into the role of each of these guidelines and why they’ve been deemed important factors in the management of IBS.

Adjusting Fibre Intake

One of the most important things we work on with our clients is adjusting fibre intake. In most cases this means increasing the total amount of dietary fibre our clients eat each day. Health Canada estimates that most Canadians are only consuming around half of their recommended daily fibre intake (25 g for females & 38 g for males). However, it’s not only about increasing fibre intake, but also understanding what types of fibre you might need more or less of for your particular symptoms. 

Fibre is important for managing gut motility (how quickly things move through your gut) and stool consistency. When we improve these factors, we usually also see an improvement in other IBS symptoms such as bloating, urgency, and pain. Dietary fibre is found in all plant-based sources – vegetables & fruits, whole grains, nuts & seeds and legumes. There are also synthetic (man-made) fibre supplements on the market, which are commonly used in IBS and other digestive disorders.

There are different ways to classify fibres, all of which have different effects on our bowels. In particular, we can classify different fibres according to their solubility, viscosity, and fermentability.


This describes a fibre’s ability to absorb water or dissolve in water. This can improve the consistency of stool and help it move through the bowels. For someone with diarrhea, a more soluble fibre is usually best, as it helps to absorb excess water, bulking up stool, and improving stool consistency. For someone with constipation, soluble fibre can help to soften stool, while insoluble helps to bulk and move stool through the bowels quicker, keeping bowel movements regular – because it does not dissolve in water.

Some examples of soluble fibre sources are: legumes, oats, psyllium, ground flaxseed, and chia seeds.

Some examples of insoluble fibre sources are: nuts, seeds, flaxseed, fruit with skin, legumes, wheat bran, lignin, and cellulose


The viscosity of fibre is defined as its ability to form into a gel-like substance. Fibres that are more viscous will thicken when mixed with fluids. For diarrhea, more viscous fibres can slow down how quickly stool moves through the digestive tract. For constipation, the viscosity of fibre can help to keep stools from getting too dry. Only soluble fibres can be viscous, as insoluble fibre doesn’t attract water. However, not all soluble fibres are highly viscous.

Some examples of viscous fibre sources are: psyllium, pectin, and beta-glucan (this can be found in oats!)1


This describes whether the fibre will be broken down by colonic bacteria into gas. When fibre is fermented by out gut microbiota in the large intestine, it can provide health benefits. However, fibres that are highly fermentable can sometimes worsen symptoms of IBS like gas, bloating, distention, and abdominal pain.

Some highly fermentable fibre sources are: FODMAPs (particularly fructo-oligosaccharides and galacto-oligosaccharides), resistant starch, inulin, pectin, and guar gum.

Some lower fermentable fibre sources are: cellulose, sterculia, wheat bran, lignin, and psyllium

There are some simple ways to add more fibre into your diet such as aiming for half a plate of vegetables at lunch and dinner, snacking on fruit or nuts, adding chia seeds or ground flaxseed to your yogurt or smoothie, and choosing plant-based proteins such as legumes, nuts & seeds more often.

Fibre supplements can also be useful in meeting your fibre guidelines and managing IBS. But, we always start with a food first approach.

Increasing Fluid

When increasing fibre, we also need to increase water intake to keep stool soft and prevent constipation. Aiming for 2-3 L (8-12 cups) daily is a good target. Strategies such as carrying a water bottle, tracking intake with an app, and pairing water with meals and snacks can help you increase your daily intake.

Limiting Caffeine, Alcohol & High-Fat Foods

Classic IBS advice has focused on moderating intake of caffeine, alcohol and high-fat foods. While individual tolerances to these categories vary, it’s a great place to start making adjustments to your diet.

Alcohol impacts the quantity and diversity of gut bacteria and damages the gut mucous lining. Drinking alcohol, especially in excess (greater than 4 drinks/day), is associated with increased IBS symptoms including diarrhea, stomach pain, and nausea.2 Additionally, anything carbonated could increase bloating and gas, worsening IBS symptoms. 

Caffeine increases gastrointestinal motility which can lead to urgency and a shift in stool consistency.3 People with IBS may need to moderate their intake of caffeine from sources such as coffee, green and black tea, pop, energy drinks and chocolate. However, in IBS-C, caffeine may help to stimulate a bowel movement and could be considered a tool in IBS management.

a clear vase with greenery, a gold spoon, and a coaster with a white mug of coffee sitting on top of a white marble tabletop with a vase

The role of fat in IBS is not clearly established. However, many studies have indicated an increase in symptoms (abdominal pain, distension, and bloating) when consuming high-fat meals.4 We frequently find that high intake of high-fat foods displaces intake of more nutrient dense, high fibre foods. High-fat foods include deep-fried foods, ice cream, and pizza but also include healthier options such as avocado, coconut oil, cheese, and meats.

Because individual tolerance to these triggers varies widely, consider using a food journal and monitoring for your current intake of these potential triggers. Use the philosophy “cut back, not cut out”. Full restriction of these are often not required. A reduced amount from your current intake is often enough to reduce symptoms.

Avoiding Sugar Alcohols

Sugar alcohols (also called polyols) are artificial sweeteners found in sugar-free chewing gums, candies, mints, drinks, and diet products. These can have a laxative effect in the small intestine and therefore it is recommended to avoid them with IBS. Particularly if prone to diarrhea. 

In particular, the NICE guidelines suggest limiting sorbitol. But, it can also be beneficial to avoid foods containing mannitol, maltitol, and xylitol.

Limiting Fresh Fruit to 3 Portions Per Day

Although the NICE guidelines don’t clearly define why they’ve made this suggestion, it does make sense according to what we know about the types of sugars naturally present in fruit. Most fruit contains some natural polyols as well as a sugar called fructose. In large amounts, these could lead to digestive distress, particularly loose and urgent bowel movements. 

Have you ever eaten too many cherries or pieces of watermelon in the summertime when they’re fresh and delicious? You may have noticed an increase in bowel movements. They can also increase gas and bloating. As the carbohydrates found in certain fruits pull water into the gut and ferment. This can be particularly noticeable in those with IBS if they eat large amounts of fruit in a short period of time! 

Having Regular Meals: Meal Spacing & Mindful Eating for IBS

While we often focus on what we eat for IBS management, we rarely consider when we eat. Skipping meals or eating very light during the day leads to eating large dinner portions and/or raiding the pantry for extra, often less nutrient dense snacks. Larger intake at one time can lead to bloating and indigestion. If you find your symptoms build during the day and are highest in the late afternoon/evening, consider redistributing your food throughout the day.

The simplest way to do this is to include three balanced meals, and snacks as you notice your hunger. In fact, responding to hunger and fullness (eating when you’re hungry, and stopping when you’re full and satisfied), while working on meal spacing is often enough to improve IBS symptoms immensely. Easier said than done, which is where dietitians can help!

After you’ve focused on the ‘when’ you eat, you should also consider the ‘why and how’. Slowing down, chewing our food, and savouring the taste and flavours can help to improve digestion. After all, digestion starts in the mouth by chewing! Setting aside time to eat without distraction and notice how your body feels can greatly reduce IBS symptoms.

The Mediterranean Diet for IBS

Aside from the low FODMAP diet and the NICE dietary guidelines for IBS, are there other diets that have evidence to help with IBS management? Yes! Although many trendy fad diets may claim to help with IBS, most of them lack the research to actually back up that claim. One diet that DOES have promising results is the Mediterranean diet. Which is a dietary pattern typically used to reduce inflammation in conditions such as heart disease, fatty liver disease, or arthritis. 

Compared to a low FODMAP diet and the NICE guidelines, the Mediterranean diet performed equally as well for the management of IBS symptoms.7

Other Dietary Considerations

Aside from the low FODMAP diet and the diets listed above, there are a few other key nutrition basics to consider for the management of IBS.


Probiotic supplements may help but it’s important to match the right strain to the right person for the right reason. We always suggest discussing probiotic supplements with your health care provider to ensure you are not wasting your money and achieving the desired effect.

Dietary Variety

Fuelling the bacteria in our gut is more important than taking a probiotic for gut health specifically. Recent results from the American Gut Project showed that people who ate a wider variety of plant-based foods had an increased diversity of their gut microbiota.5 Observational studies found decreased gut diversity in a variety of diseases including celiac disease, irritable bowel syndrome, inflammatory bowel disease, and diabetes.6

To increase the variety of plants you eat, try a new recipe weekly, pick out a new vegetable or fruit when shopping, and aim for at least 2 colors of vegetables on your plate.

Avoiding Spicy Foods

Spicy food can cause indigestion and stomach upset. Most spicy foods contain capsaicin, a naturally occurring compound in peppers. This can aggravate our gut lining, speed up digestion, and activate pain receptors in the gut.

Take Home Message

IBS care doesn’t have to start RIGHT with the low FODMAP diet. Simpler strategies can be tried first to see how good you can feel. Practicing these consistently can make a large impact on IBS symptoms and for many people will eliminate the need for further dietary restriction.

However, for some whose symptoms are still not controlled, working with a specialized dietitian on the low FODMAP diet is often the next step. At Ignite Nutrition our Dietitians specialize in helping clients navigate the basics of IBS management, and are experts in the low FODMAP diet. 

And don’t forget, there are other aspects of IBS management aside from just food. Things like stress management, medications, and sleep are also important. Which is why we use our 4-pillar approach to IBS at Ignite Nutrition. If you’re ready to take charge of your IBS – get the support YOU need by working with one of our registered dietitians today!

FAQs About IBS Nutrition Basics

What triggers IBS symptoms?

IBS symptoms can be triggered by certain foods and drinks like caffeine, alcohol, high fat foods, spicy foods, or artificial sweeteners called sugar alcohols. Many people also find foods high in fermentable carbohydrates called FODMAPs aggravate their IBS symptoms. Stress, poor sleep, and eating at irregular times may also trigger IBS symptoms.

What is the best diet for IBS sufferers?

A low FODMAP diet is good for managing IBS, but can be restrictive and difficult to follow and may not be appropriate for everyone. Other evidence-based diets shown to help with IBS are the NICE diet guidelines for IBS and the Mediterranean diet. Learn more about diet basics for IBS.

What are the best supplements for IBS?

Some common supplements used in the management of IBS include peppermint oil capsules, probiotics, enzyme replacement supplements, and fibre supplements such as psyllium or partially hydrolyzed guar gum. This will vary depending on the individual and their symptoms. 

Categorized: Gut Health & IBS

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