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Fatty ice cream cone

Common IBS
Food and Drink Triggers

Everybody is different, especially when it comes to IBS, but some foods and drinks are common triggers for IBS symptoms.  After making sure you're eating a healthy and balanced diet and taking a look at your eating habits, investigating common IBS food and drink triggers is a good next step.

To find out more about common IBS food and drink triggers and why they may be affecting your digestion...

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Common Food and Drink Triggers

Common IBS triggers - ice cream, spicy food, alcohol, caffeine, soda

Obviously your diet can have a big impact on your IBS symptoms, but it can be hard to pinpoint exactly what's triggering them.  Meals are made up of many different foods, there are many ways that food can affect your gut and there is always a delay between eating and symptoms.

Keeping a food and symptom journal or tracking on an app is a good place to start.  If you start to notice a pattern, then try cutting out or cutting down on your main suspect.  Don't eliminate everything at once, because you'll never figure out the real culprit and remember that with IBS the amount counts!  You may be able to tolerate a little of something, but not a lot, or more when you're not feeling stressed or hormonal.

The goal is to include as many things in your diet as you can, while still managing your symptoms.  


This stands for Fermentable Oligo-Di-Mono-Saccarides And Polyols.

FODMAPs are short chain carbohydrates found in lots of different foods, including fruit, vegetables, grains, nuts, beans and dairy.  

Often these carbs are not absorbed very well in the small intestine, or not absorbed at all.  They can drag water into the intestine, causing diarrhea.  When they move into the large intestine, they become dinner for your gut bacteria.  This creates gas that stretches the wall of the intestine, causing pain and other IBS symptoms.

FODMAPs are currently all the rage in IBS treatment.  It's a huge topic and you can find out more in The FODMAP Elimination Diet section. 

FODMAP foods - honey, peas, butternut squash, garlic, pasta, apple, almonds, beans


Fatty foods - pizza, ice cream, meats and cheese

Fat can affect digestion in a number of ways and can be a trigger for both constipation and diarrhea, as well as other IBS symptoms.

Fats are more difficult than other nutrients for your body to digest.  They take longer to go from one end to the other and this slowing of digestion can make constipation worse.  Slower digestion also means that gas may get trapped in the gut and start to build up, causing discomfort or pain.

The majority of fat digestion takes place in the small intestine.  When you eat fat your body releases bile into the small intestine to help break it down.  The more fat you eat, the more bile gets released.  Normally the intestine reabsorbs the components of bile after they do their job, but if there is a problem here then the bile stays in the intestine and draws water in.  This can lead to diarrhea and bloating.

Diarrhea and a sudden urge to run for the bathroom can also be affected by your gastrocolic reflex (GCR).  The GCR is a normal reflex triggered by eating.  It increases movement in the colon to "make room" for the food you've just eaten.  A larger stretch of the stomach from a big meal or a large amount of fat can send a stronger signal.  Some people with IBS-D already have an exaggerated GCR and this can make matters even worse.

Fat is an essential nutrient and your body needs it for many things.  So instead of cutting out fat entirely, try not to have too much in one meal or in one day and eat healthier fats like those found in vegetable oils, nuts, seeds or fatty fish.  Check out the Tips for Healthy Balanced Eating section for more info.


Caffeine is a stimulant that has a direct effect on the central nervous system and on the gut. It's of course found in coffee, but also in tea, dark chocolate, energy drinks and pop.

Many studies use coffee and have shown that it increases motor activity in the colon.  Interestingly there was also an increase with decaffeinated coffee, although not as much.  So if you suffer from cramping and diarrhea. you may want to cut down on caffeine to see if that helps.  If you drink a lot of caffeine you may want to cut down slowly to avoid withdrawal symptoms.  On the other hand, if you suffer from constipation caffeine may help to get your bowels moving.

Some studies have linked caffeine to nervousness and anxiety, while others show a calming effect at a low dose.  Anxiety is linked to IBS through the gut/brain axis.  If you think caffeine might be making you edgy, then consider reducing your intake.

Cup of coffee


Tall blue cocktail

Alcohol is a depressant that has a direct effect on the central nervous system and on the gut.  It is also a known gut irritant.  Alcohol affects movement and absorption of nutrients in the intestines.  It can damage your intestines and change your microbiota.

Alcohol also changes the speed of gastric emptying, or the rate at which contents empty out of your stomach.  Some research shows that it speeds up when the alcohol content is below 15% (beer or wine), which could cause diarrhea and slows down above 15% (spirits)' which could lead to constipation.

Alcohol is also a diuretic, which means that it draws water from the body and you have to pee a lot.  Dehydration can cause constipation.

Some alcoholic beverages contain FODMAPs, which may make your symptoms worse if you are sensitive to them.

About a third of people with IBS report that alcohol makes their symptoms worse, so definitely something to look out for.  To help with symptoms drink on a full stomach so absorption is slower, drink plenty of water and choose non-carbonated mixers.

Carbonated Drinks

Carbonation in beverages can increase pressure in the gut due to aerophagia, or excessive air intake.  This increased pressure can cause bloating and visceral hypersensitivity (pain). 


You could also try ditching the straw, as this can also add extra air to your gut.

Can of soda pop

Spicy Foods

Chili pepper on fire

Spicy foods are also a common gut irritant.  This is due to a compound called capsaicin, found in things like chilis and pepper.  This compound is thought to accelerate GI transit time, or the speed things move through your gut.  This could possibly help with constipation, but it's not such good news if you suffer from diarrhea.

Capsaicin can also cause abdominal pain and a burning sensation when it comes into contact with a certain receptor (TRPV1) in your gut walls.  It's thought that some people with IBS may have more of these receptors in their gut lining, making them more sensitive.

Before you swear off spicy foods forever, keep in mind that most meals are made up of many different kinds of food.  For instance, a spicy curry probably has lots of onions and garlic, which contain FODMAPs.  Or it may be high in fat, which can trigger diarrhea or constipation.  If you'd like to keep some spice in your life, you could try experimenting with different food combinations.


Fibre is a type of carbohydrate your body can't digest, so it passes through your digestive tract.  

There are 2 main types of fibre, soluble and insoluble.  Soluble fibre dissolves in water and can swell to form a thick, jelly-like substance in the gut.  Insoluble fibre does not dissolve in water and is what we typically think of as roughage.  Most plants have both, some with higher concentrations of one or the other.

The Canadian guidelines for fibre are 25g a day for women and 38g for men.  It's estimated that on average most Canadians are only getting half that much.  The guidelines do not differentiate between soluble and insoluble fibre.

Fibre and IBS

In the past IBS sufferers were often told to increase their fibre intake to help with constipation and diarrhea.  On the surface this is good advice, as most of us could do with more fibre in our lives.  However, it turns out that the type of fibre is very important when it come to IBS. Fibre can be a great help, but it can also be a trigger for IBS symptoms.

Soluble fibre slows down transit time in the gut and can bulk up and soften your poo making it easier to pass, so it can be good for both diarrhea and constipation.  Insoluble fibre increases the bulk of your poo, but it also physically stimulates your intestines causing things to move through more quickly.  This could be good for constipation, but for people with motility problems and an overly sensitive gut this stimulation may translate as pain.  Insoluble fibre generally increases transit time through the gut, which isn't helpful if you have diarrhea.

Many foods containing fibre are also high in FODMAPs.  If you are sensitive to FODMAPs, increasing intake of these foods could make your symptoms worse.  There are other types of fermentable fibre, like resistant starches, that aren't classified as FODMAPs that may also cause IBS symptoms.

Fibre tolerance varies from person to person and sometimes too much of a good thing can be bad.  Some studies have shown that a lower fibre diet might work better for some people with IBS, especially if symptoms are more severe.  Best to consult a dietitian before starting a low fibre diet to make sure you're still getting the nutrients your body needs.

If you have IBS and want to increase your fibre intake:

  • Start with foods higher in soluble fibre

  • Consider high soluble fibre and low FODMAP options like psyllium

  • Increase fibre slowly (no more than 5g per week) and pay attention to your symptoms.  Are they better or worse?

  • Drink plenty of fluids

For more information about fibre and IBS see the Tips for Healthy Balanced Eating section.

For more information about fibre and FODMAPs see The FODMAP Elimination Diet section.

Fibre sources - nuts, orange, sweet potato, oatmeal, bread, lentils

Sugar Alcohols (Polyols)

Sugar free

Sugar alcohols are common sweeteners used as sugar substitutes in some sugar free gums and candies, low cal or "lite" packaged foods and medicines.  They often end in "ol" and examples are sorbitol, mannitol, xylitol, maltitol, lactitol and erythritol. Isomalt is a sneaky one made up of sorbitol and mannitol.  Sugar alcohols can also occur naturally in foods, like cauliflower or mushrooms.

Sugar alcohols are not digested in your GI tract.  They pull water into your intestines, possibly causing diarrhea.  They are then fermented by your gut bacteria, possibly causing bloating and distension.  Normally this would only happen if you ate large quantities.  But if you have IBS and your gut is overly sensitive, they could cause problems at a lesser amount.


Sugar alcohols, or polyols, are the "P" in FODMAPs.  You can find out more about them in The FODMAP Elimination Diet section. 

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