Eric Bakker N.D.April 27, 2022

Irritable bowel syndrome (IBS) affects the large intestine and is a prevalent condition. Cramping, abdominal pain, bloating, gas, and diarrhoea or constipation, or both, are signs and symptoms. IBS is a long-term condition that you'll have to deal with.


A cornerstone of amazing health is a great diet. Eating fresh and healthy has been a focus in my life for over forty years, and one of the most important habits as a naturopath I’ve tried to instill in our patients. To be well and stay well, you will need to eat well too, and it is encouraging many people are realising the importance of nutrition for health.

This is especially important if you have irritable bowel syndrome (IBS).

A healthy and nutritious diet comprises consuming a wide variety of foods high in nutrients, including fruits, vegetables, nuts and seeds, legumes, etc. Unlike others, people who have irritable bowel syndrome may notice some foods cause them to have uncomfortable digestive symptoms and need to be more careful with their selection of foods.

More than half of IBS patients have self-reported food intolerances and worsening of symptoms after consuming certain foods. Others with IBS notice most symptoms occurring within 3 hours of eating a meal. Gas problems and abdominal pain are the most commonly reported symptoms.

After working in the clinic with IBS patients for many years, I noticed the range of foods those with IBS can tolerate can vary from person to person. Yet there is a certain group of foods you will find listed below have a tendency to be the most problematic. Those with IBS will relate to several of these foods.

I learned people with IBS will be quick to list the foods affecting them. Because the precise foods that cause IBS vary from person to person, it is almost impossible to compile an exact and comprehensive list of foods to avoid with IBS.

According to a 2016 study Addressing the Role of Food in Irritable Bowel Syndrome Symptom Management, the most common foods reported as IBS symptom triggers include:

  • Fruits (citrus, banana)
  • Grains (wheat, barley, rye, oats, corn)
  • Vegetables (onions, peas, potatoes)
  • Dairy products (yogurt, milk, cheese, eggs, butter)
  • Legumes (beans, lentils)

Alcohol, chocolate, coffee, tea, and fried foods

Stop eating junk first

People living with IBS will discover that avoiding poor food and beverage choices like dairy foods, alcohol, soda drinks, candy, sugar, ice cream, pizza, take away foods, and fried meals can cause significant benefits. And these benefits will become apparent long before healthier food choices stop because you discovered them to be poor food choices.

I discovered as a naturopath it was quite common to discover an IBS patient who still consumes regular take away foods and who even drinks alcohol regularly, but who avoids cauliflower, onions, garlic or beans because they “appear to aggravate” their gut symptoms. Stop all alcohol entirely and no take-away foods please, before you stop any natural foods like cauliflower.

It takes time to improve the digestive system. Gut bacteria grow in large colonies and need ideal conditions to flourish. By eliminating crappy food and drink choices foremost, you will improve your stomach and bowel function. Does this make sense?

  • Gut improvements by eliminating junk:
  • Bowel movements become more regular
  • Bowel motions are better formed
  • Less cramping and bloating
  • Big reduction in gas
  • Enormous increase in gut comfort
  • Easier to manage weight

Continue to read to find out my top foods that may contribute to your IBS symptoms becoming more severe. I would recommend that you avoid most of these foods, if not all, to begin with. You can always add them (the healthy food choices) back in at a later date. An elimination and challenge diet is an intelligent approach if you want to improve digestive comfort.

1. Dairy Foods

I’ve always found dairy foods to be problematic in irritable bowel syndrome. There are several reasons these foods may cause problems in people with IBS.

First, cow’s milk is food with a high potential to be a significant food intolerance or allergy in many people, and second, dairy foods are high in fat, which can lead to diarrhea. Switching to oat or another non-dairy milk may reduce your symptoms.

The third reason is cow’s milk is a trigger for many people, although it is unclear if people with IBS have are more likely to have lactose intolerance.

Some people recommend A2 cow’s milk, a product with the allergic A1 protein removed. Second, some people with IBS report milk is a trigger for their symptoms, though it’s unclear if people with IBS are more likely to have true lactose intolerance.

My recommendations to switch to dairy-free milk and cheese alternatives, there are many available today. When I started working with patients in my naturopathic clinic many years ago, the only alternative was soy milk. Today, many kinds of nut and seed milk are available. I’m noticing a few of the larger dairy companies have already started smear campaigns against many milks that are not cow-related. The same thing happened in the 80s when soy milk became increasingly popular, and today has many consumers world-wide. Many women in Western countries, especially women with menopause, benefit from a glass of soy milk daily.

Some people get concerned about developing a calcium deficiency if they cut out all dairy products, but today there are a good deal of calcium-rich foods available which are non dairy, such as

First, cow’s milk is food with a high potential to be a significant food intolerance or allergy in many people, and second, dairy foods are high in fat, which can lead to diarrhea. Switching to oat or another non-dairy milk may reduce your symptoms.

The third reason is cow’s milk is a trigger for many people, although it is unclear if people with IBS have are more likely to have lactose intolerance.

Some people recommend A2 cow’s milk, a product with the allergic A1 protein removed.

Second, some people with IBS report milk is a trigger for their symptoms, though it’s unclear if people with IBS are more likely to have true lactose intolerance.

My recommendations to switch to dairy-free milk and cheese alternatives, there are many available today. When I started working with patients in my naturopathic clinic many years ago, the only alternative was soy milk. Today, many kinds of nut and seed milk are available.

Some people get concerned about developing a calcium deficiency if they cut out all dairy products, but today there are a good deal of calcium-rich foods available which are non dairy, such as


  • Greens vegetables
  • Sardines
  • Many nuts and seeds

2. Fried foods

French fries and other deep-fried foods are common in the typical Western diet. However, eating too much can cause health problems. The high fat content may be hard on the system for people with IBS. Often this fat will be of poor quality.

A study of 300 patients with IBS revealed 44% attributed the consumption of fatty foods (deep-fried foods, french fries, pizza and cream) with the induction of symptoms (Simren, 2001). Another study found just over half of participants with IBS believed they triggered symptoms after consuming fried or fatty foods (Bohn, 2013).

Frying food can change the chemical makeup of the food, making it more difficult to digest, which leads to uncomfortable digestive symptoms. Fried foods also have less nutritional value than non-fried foods and are high in calories, leading to excess weight gain if they consumed too many fried foods.

For a healthier option, try grilling or baking your favorite foods instead. The best option is to avoid all fried and fatty foods until your digestion has improved before consuming these foods again. The only frying I recommend is shallow frying in EVOO, extra virgin olive oil, and never use the oil twice.

3. Insoluble fiber

Besides bulking up the diet, dietary fibre aids in gut health. The following foods are high in dietary fibre:

  • Unprocessed whole grain foods
  • Vegetables
  • Fruit

Foods include two kinds of fibre: soluble and insoluble.

We can find insoluble and soluble fiber in most plant foods, including fruits and vegetables. However, some foods are more concentrated in one.

Beans, fruits, and oat products contain the most soluble fiber and are likely the more problematic foods with IBS.

Most of the insoluble fibre we eat comes from plant sources, like whole grains and vegetables.

Most patients with IBS can benefit from soluble fiber, which dissolves in water. Psyllium and inulin are both water soluble, according to a Monash University study, but inulin ferments and may exacerbate IBS symptoms. Many IBS patients benefit from psyllium, however, and if you can’t tolerate various fruits and vegetables but want to increase your dietary fiber intake, consider adding psyllium to your diet.

As for wheat bran, dieticians believe it can cause pain and bloating because of its insoluble fibre content.

Fiber, one size does not fit all

When you work with many patients with IBS over several years, you observe various people have different levels of tolerance for fibre. Some persons with IBS experience worsening symptoms while eating meals high in insoluble fibre; others with IBS have no problems eating these foods. Irritable bowel syndrome (IBS) sufferers should be aware certain meals high in soluble fibre, such as beans, can also exacerbate symptoms.

So what are you supposed to do? As you can see, diet and IBS need to be individualised, and certain fiber-rich meals may not agree with you while other may help symptoms, as you have seen.

What is the solution? It is trial and error, and only by experimentation will you find out what works for you. You could also try taking soluble fibre pills or powder to assess if this is right for you.

My belief is the quality and quantity of bacteria (both good and bad) in the small bowel handle how the person feels after consuming any foods.

If your gut bacteria are in balance, you should be able to consume a wide range of foods containing both soluble and insoluble fiber. When they are out of balance, you’ll be having issues, and the bigger the imbalance, the bigger the issue. I’ve always recommended for this reason IBS patients consider a comprehensive stool test to assess the gut bacteria.

4. Gluten

Gluten is a group of proteins present in the grains of rye, wheat, triticale, and barley, and they have linked it to IBS symptoms in certain persons. They also claim oats contain gluten, when they don’t, but because they package oats in factories where they pack gluten containing grains, they can become contaminated with traces of gluten.

Some people’s bodies develop a severe immunological reaction to gluten called celiacs disease, causes them to become quite ill. Others may experience symptoms ranging from mild to severe after consuming gluten, yet be suffering from gluten intolerance and not celiac disease. The symptoms of this autoimmune disorder are like those of diarrhea-predominant IBS, and they can sometimes misdiagnose both until tests confirm otherwise.

Celiac or gluten intolerant?

Celiac disease is an autoimmune condition affecting the small intestine. It is a lifelong condition. It influences the intestinal cells, resulting in a reduced ability to absorb nutrients. Unlike celiac disease, the reasons for gluten intolerance, also known as non-celiac gluten sensitivity, are less well understood.

A 2016 study revealed a gluten-free diet helps ease IBS symptoms in almost half of those who take part.

I recommend that people suffering with IBS attempt to eliminate gluten to see if their symptoms improve. If you discover gluten exacerbates your symptoms, you may wish to experiment with a gluten-free diet for some time. This may range from 3 months to a year or longer. My recommendations are not to avoid gluten “for life” unless they have diagnosed you as celiac.

People living with IBS who are gluten intolerant may find it difficult to receive the amount of fibre they need, and my recommendations are they should focus on gluten-free grains such as quinoa.

Oats, millet, buckwheat, and wild rice are all possibilities as well, so experiment. Remember, if you’re buying oats, be careful to double-check the label for wheat contamination, but I’ve not found oats to as much of a problem as other grains in those with IBS.

The good news is a growing number of gluten-free items are being introduced to the market at an astonishing rate. If you cannot live without pizza, spaghetti, cakes, or cookies, you may always swap gluten-free alternatives for them.

There are a variety of full, healthy alternatives to gluten-containing grains and flours available, such as the ones below:

  • Oats
  • Buckwheat
  • Quinoa
  • Sorghum
  • Coconut flour
  • Almond flour

5. Alcohol

Alcoholic beverages are a typical source of discomfort for those suffering with IBS. This is because of the way the body digests alcohol. Alcohol can cause dehydration, which might have a significant impact on digestion.

Beer is a problematic choice since it includes gluten and yeast, while wines and mixed drinks can contain large quantities of sugar, making them a poor choice for those with IBS who want to eliminate cramps, bloating and gas. Alcohol and sugar increase the likelihood of causing many potential digestive symptoms in those with IBS.

A study conducted in 2012 regarding alcohol consumption and digestive symptoms among patients with irritable bowel syndrome found they did not associate light to moderate drinking with GI symptoms. However, the strongest associations for IBS patients were between binge drinking and the following day’s GI symptoms: diarrhea, nausea, stomach pain, and indigestion.

Keep alcoholic beverages to a minimum will help alleviate symptoms associated with IBS. I do not recommend drinking alcohol with IBS unless you have your symptoms well under control and have made a healthy diet change as well.

If you want to consume alcohol, I would recommend trying gluten-free beer or a drink made with pure seltzer and without artificial sweeteners or any added sugar. Neutral spirits in moderation, like gin and vodka, are better than beer, wine, and spirits like rum or whiskey.

6. Caffeinated drinks

Have you noticed some people swear by their morning cup of coffee to keep their digestive system normal? Caffeine-containing foods and drink stimulates your colon, the likely reason you are making a dash to the bathroom after your morning cup.  In one study published in 1990 in the journal Gut, 92 young adults filled out a questionnaire about how coffee affected their bowel habits; just 29 percent of the respondents said it “induced a desire to defecate,” and most of them — 63 percent — were female.

However, coffee, like other caffeinated beverages, has a stimulating impact on the intestines and can cause diarrhoea in some people.

Caffeine-containing beverages such as coffee, sodas, and energy drinks are some of the most frequently reported trigger foods in patients with IBS.

If you need an energy boost or pick-me-up, consider having a small snack or taking a short stroll instead of drinking coffee.

7. Beans and legumes

Beans, lentils, and peas are considered being a good source of protein and fibre, but they might aggravate IBS symptoms in some individuals. They include oligosaccharides, which are sugars resistant to breakdown by digestive enzymes and are thus harmful.

Your gut bacteria will determine to what degree you will be able to break down these sugars. And because gut bacteria can vary from person to person, the ability to tolerate beans and legumes can vary.

While beans can assist relieve constipation by adding bulk and weight to the stool, in some IBS people, they can increase the following:

  • Bloating
  • Cramping
  • Gas
  • Loose stools

To test whether it helps your IBS symptoms, try eliminating all beans and legumes for a few weeks. Don’t forget, when eating beans or lentils, always soak them overnight, then wash them before cooking them. This will make them easier to digest and help reduce symptoms like gas, cramping and bloating.

8. Processed and take-away foods

It is essential you study nutrition labels if you want to get to the root of your stomach problems. Some of your favourite convenience foods and flavourings — such as cereal, soups, spice mixes, salad dressings, and frozen dinners may include high amounts of sugar or artificial sweeteners, so be cautious when purchasing these items.

For example, the terms “natural flavours” and “dehydrated vegetables” in a spice mix may contain high levels of garlic or onion powder, while the term “sweeteners” in a dressing could refer to many kinds of artificial sugars. If you are worried or concerned about any food or beverage product, a quick Google search will provide you with enough information to make a more informed decision.

My naturopathic approach to providing information about food and IBS over the years has always been the same – eat foods as fresh and as close to their natural state as possible, that way you will not only be avoiding most if not all unnecessary additives or ingredients.

You will also provide your body with all the most essential elements, like vitamins and minerals, if you eat a wide variety of fresh foods, including fruits, vegetables, nuts and seeds, protein sources and fats.

Processed foods and take-away contain a lot of added salt, sugar and fat.

Examples of processed and take-away foods include potato chips, pre-made frozen meals, processed meats like salami and bacon, and deep-fried foods like french fries, nuggets and fried chicken.

When possible, making meals at home or buying fresh produce is a healthful alternative to buying processed foods. And it is also a lot more cost saving, money you can spend on other things. As mentioned, if you want to fry foods, try frying in a little olive oil.

The processed food category is one category I prefer everybody to avoid as much as possible, regardless if you have IBS or not. Eating too much of the ingredients found in these foods can lead to health problems for anyone. In addition, they often contain additives or preservatives that can trigger bowel flare-ups in those with IBS and inflammatory bowel disease like ulcerative colitis.

A 2009 study explains the link between consuming take away foods twice a week or more and abdominal obesity in young men and women.

In a study conducted ten years later in 2019 study they found eating 4 servings of processed foods daily linked to a higher risk of developing IBS, along with a chronic illness like high blood pressure, obesity and cancer.

9. Chocolate

Chocolate bars and candy might exacerbate IBS symptoms, since these processed foods often contain high levels of sugar and fat, as well as containing lactose and artificial sugars and even caffeine sometimes.

I’ve found in most cases people who suffer with IBS stay away from chocolate and chocolate-flavored foods. Those who only experience mild symptoms of IBS may consume chocolate, unaware it may cause subtle symptoms of bloating, cramping or gas.

When some people with IBS consume chocolate, they may have constipation, others can develop diarrhea.

More recently, several vegan chocolate choices for chocolate lovers have become available, are more bearable for folks who have IBS.

10. Broccoli and cauliflower

It’s hard to think fresh produce, which is high in disease-fighting nutrients, could be the root of your digestive problems. Unfortunately, certain fruits and vegetables, include oligosaccharides, monosaccharides, and polyols, upset your stomach.

Eating raw broccoli and cauliflower can irritate the digestive system of those with IBS. A suitable alternative is to consider roasting or sauteing these vegetables instead.

Even for persons who do not have IBS, the breakdown of these meals generates gas and, sometimes, constipation or irregular bowel motions.

I’m a believer in the consumption of brassica vegetables. Many studies confirm the important role they play in health. A 2017 study for example, mentioned that increased consumption of Brassica vegetables is linked to a reduced relative abundance of sulphate-reducing bacteria and an increase in lactobacilli bacteria, and therefore may be potentially beneficial to gastrointestinal health.

Here are vegetables from the brassica family. I have found some problematic, but that can widely vary from person to person.

  • Broccoli
  • Cabbage
  • Cauliflower
  • Bok choy
  • Brussels sprouts
  • Kale
  • Mustard

11. Garlic and onions

Garlic and onions make some of the best flavouring agents in your kitchen, but can be tough for your digestive system to handle.

They are both linked with causing painful gas and cramps and even processed versions such as dried and powdered garlic and onions are sometimes triggers.

Irritable bowel syndrome patients may have difficulty breaking down the fructo-oligosaccharides (also known as fructans) found in garlic and onions. If the stomach and small intestine cannot digest certain foods, fermentation occurs in the large intestine, resulting in bloating, gas, and stomach discomfort.

Avoid garlic and onions if they cause a problem with your digestive system. As you improve your diet and lifestyle over a period, your digestive system will also improve. This can allow the time your gut needs to build and to tolerate foods it previously couldn’t.

12. Sugar and sugar-free sweeteners

Most with IBS will be aware white, raw or brown sugar is not the greatest choice as a sweetening agent. In fact, it’s downright shocking. People are looking for sugar substitutes.

We can find high fructose corn syrup in sugary beverages and commercial sweets containing, which are both terrible for our health. While they are often the source of bloat and gas in persons with IBS, they are not the sole source of discomfort.

For sugar replacements like sorbitol and xylitol (found in sugar-free gum and mints), IBS doesn’t discriminate: honey, agave nectar, high fructose corn syrup, and sugar substitutes like sorbitol and xylitol (found in sugar-free gum and mints) may all cause problems.

Because they’re all high in difficult-to-digest carbohydrates, the bacteria in your stomach may ferment them, causing IBS symptoms.

Sugar-free doesn’t mean it’s “good for your health”, especially for IBS. Sugar-free sweeteners can be found in sugarless candy, chewing gum, diet drinks and mouthwash.

Sugar substitutes include:

  • Sugar alcohols
  • Artificial sweeteners
  • Natural zero-calorie sweeteners

Sugar alcohols

Sugar alcohols are sweeteners have about half the calories of regular sugar. They occur naturally in certain fruits and vegetables, but many are artificial and added to processed foods. Common sugar alcohols are mannitol, sorbitol, xylitol, lactitol, isomalt, maltitol and hydrogenated starch hydrolysates (HSH).

We do not use sugar alcohols in home food preparation, but found in many processed foods you will find in your supermarket. Be careful, many foods labeled “sugar free” or “no sugar added” have sugar alcohols in them.

The primary issue with sugar alcohols is they can produce gastrointestinal adverse effects in persons with and without digestive disorders such as irritable bowel syndrome, when consumed in large doses regularly. Try to identify any sources of sugar alcohols in your diet if you continue to have digestive problems, yet cannot find the source of the problem.

Artificial Sweeteners

An artificial sweetener is a food ingredient that mimics the taste of sugar while containing fewer calories than sugar in most cases. Animal studies have showed artificial sweeteners induce weight gain, brain tumours, bladder cancer, and a variety of other health problems.

Five FDA-approved non-nutritive sweeteners include saccharin, aspartame, acesulfame potassium, sucralose, and neotame. They regulate each of these as a food additive.

Sugar substitutes such as aspartame (Equal and NutraSweet), sucralose (Splenda), and saccharin (Sweet ‘N Low) are among the worst offenders.

I know of many people who have reduced or eliminated artificial sugars from their diets reporting improvements in a variety of health concerns, IBS, brain fog, weight gain, and several other health issues.

Reading the ingredient labels of any sugar-free products can help you avoid these compounds.

What to do instead of FODMAPS Diet

Many doctors recommend people with IBS follow low FODMAP diets. This diet focuses on limiting foods rich in certain types of carbohydrates. Have a look at FODMAPS and IBS.

FODMAP stands for fermentable oligosaccharides, disaccharides, monosaccharides, and polyols. These are fermentable, short-chain carbohydrates.

My issue with FODMAPS is it places the IBS patient in a box and limits the foods they can consume. Experience has shown me once a doctor or dietician places a patient on a diet, they remain on the diet. As long as they remain on the diet, they remain symptom free. When they consume other foods outside the box, they don’t.

Instead of following FODMAPs and taking it as nutritional IBS gospel, why not try foods other than those listed under the FODMAPs diet as being “bad” for you?

You may find you can tolerate some of these forbidden foods with no aggravation. Every person with IBS will have a different level of tolerance to a wide variety of fruits, vegetables, grains, seed and nuts.

Functional and Diagnostic Testing for IBS

I’ve often called irritable bowel syndrome a “garbage can diagnosis”. Although your symptoms may appear quite genuine, IBS is a term applied to a collection of symptoms with no recognised explanation. There are more questions than answers in many IBS cases, for example:

  • Do I have IBS? What if it is something else?
  • Has my doctor completed any investigations into my digestive symptoms?
  • Have I had any food allergy or comprehensive stool tests completed?
  • What if I have SIBO? (small intestinal bowel overgrowth)?
  • What if I have a Candida yeast infection?

Once diagnosed, you’ll know, and be in a better position to know how to deal with it. I’ve discovered most people diagnosed with IBS have little to no guidance on how to manage their condition.

In the unlikely event you are fortunate, this generic and rather vague or scripted dietary advice may be of limited help to you. They left most people who suffer with IBS to manage their condition with no explanation about the cause.

Unless you understand why something has happened, it becomes difficult to figure out how to remedy it, and how to prevent further occurrence.

This brings me to functional medicine testing.

A test or examination of food sensitivities or food allergies are two of the most common procedures many IBS patients have undertaken. SIBO testing has become popular, with a large amount of people living with IBS relating to this condition.

Comprehensive stool testing is one of the most important tests in my professional opinion. It can reveal many potential causes of the symptoms experienced by people living with IBS, including bloating, cramping, gas, and bowel motion issues.

I learned in the clinic many IBS patients have an underlying bacterial overgrowth, Candida issues or even a parasite problem hidden for years.


Everyone’s digestion and meal triggers are different, and it is critical to remember this when diagnosing and treating IBS. Some people with IBS can handle a wide variety of foods and drinks others cannot stomach.

Learn about your body, and which meals make you feel the best. Avoid all foods that induce uncomfortable sensations and restrict your intake of those which do.

Never eat large portion sizes of any one food and cut back on how much you eat each day. Your digestive system needs a rest, and rest is an important consideration in the recovery from IBS.

Keep a food and symptom journal. It can assist you in determining which foods to consume and which to avoid.

If you require further help with your diet because of IBS, making an appointment with a registered and licensed health care professional is a wise decision, somebody with plenty of IBS experience.


Discussion (1 comment)

  1. Dear Doctor, I am suffering from IBS from last 10 years. I am not getting proper sleep and days during inadequate sleep my symptoms got worse. Also it get worse when i am in stress. I need to go to washroom 2-3 times a day. After 20 minutes of every meal i feel bloating and heavyness in my stomach. I feel sleepy and lethargic all the day. Symptoms also get worse when i do not take any food in several hours and in case of overeating. I use to burp all the day and brain fog type condition.

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