Which Foods Trigger IBS Attacks? | Lifelab Testing

Which Foods Trigger IBS Attacks?

Last Updated: 13th March 2023 · Written by Donna Mastriani

A person suffering from IBS symptoms

Irritable bowel syndrome (IBS) is a disorder that affects the large intestine and in turn the digestive system. If you suffer from IBS, you’re not alone, as 1 in 5 adults are affected by the condition making it fairly common.

IBS causes symptoms such as stomach cramps, bloating, diarrhoea, and constipation, which can last for a varying amount of time, and tend to come and go over time.

There’s currently no cure for IBS and the disorder can be difficult to live with, especially around mealtime. A change in diet, whilst frustrating, can help to improve avoiding symptoms.

Common IBS Triggers

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Discovering what your personal trigger foods are can help alleviate symptoms and give you a little more freedom when it comes to dinner time.

However, IBS isn’t a ‘one size fits all’ condition and foods can affect people differently. What’s more, it may not be practical to cut out all foods immediately – so you should instead make a list of suspect foods that you know trigger your IBS symptoms and eliminate them one by one over time to see if it makes a difference to your lifestyle.

Alternatively, our intolerance tests can identify which items may be triggering your IBS attacks to help effectively optimise your diet change. That said, here are the common foods that trigger IBS attacks:

Fried and fatty foods

High fat foods including cheese, fries, and fatty meats can be difficult on the digestive system, especially when suffering with IBS. The chemical makeup of food can be changed when frying, which can lead to uncomfortable symptoms, most notably diarrhoea.

If you’re finding it difficult to cut out these foods, grilling or baking may reduce the severity of IBS symptoms, as well as being a healthier alternative.


Dairy is an important component of a healthy diet due to it being calcium-rich. However many dairy products are high in fat which can trigger IBS symptoms. High fat dairy products can include:

  • Heavy Cream.
  • Whole Milk Yogurt.
  • Whole Milk.
  • Butter
  • Full-Fat Cheese.

It’s also unclear whether people suffering from IBS are more susceptible to lactose intolerance. However, switching to low fat dairy or dairy alternatives such as plant milks may reduce the severity of IBS symptoms.

If, for whatever reason, you need to cut out dairy altogether, make sure to include calcium rich foods into your diet such as:

  • White beans
  • Almonds
  • Sardines
  • Seeds
  • Dried figs


Found in foods such as pasta, bread, and cookies, wheat contains the gluten protein which around 5% of the population are allergic to. The symptoms produced by gluten disorders, such as coeliac disease, are very similar to IBS and therefore it’s difficult to distinguish which disorder you may be suffering from.


Fibre is a carbohydrate component of food and plays a key role in normalising bowel habits. There are two types of fibre, soluble and insoluble, and the body reacts differently to each. This means that each type of fibre can help your IBS symptoms or trigger them.

Think of fibre like a tap. Soluble fibre slows down the digestive tract which helps with diarrhoea, whereas insoluble fibre speeds up the process, relieving constipation.

Depending on your IBS symptoms, react with the correct type of fibre to help alleviate your suffering.

High fibre fruits and Vegetables
High fibre fruits and Vegetables

Soluble fibre is found in:

  • Apples
  • Peas
  • Strawberries
  • Sweet potatoes
  • Pears
  • Avocados

Insoluble fibre can be found in:

  • Blackberries
  • Broccoli
  • Cabbage
  • Leafy greens
  • Zucchini
  • Rolled oats
  • Brown rice


A piece of chocolate (or a whole bar) is often the perfect treat to satisfy that sweet tooth. However due to its ingredients containing sugar, lactose, caffeine, and typically being high in fat, chocolate can often be a IBS trigger food, leading sufferers to experience constipation.

But who really wants to cut out chocolate? Trying a plant-based alternative may help reduce the severity of your IBS symptoms.

Caffeinated and fizzy drinks

Giving up your morning coffee may be a deal breaker for most, but caffeinated drinks can often cause diarrhoea due to a stimulating effect on the intestines. Energy drinks, fizzy soft drinks and coffee can therefore be a trigger for IBS symptoms.

If you’re finding it difficult to cut these out altogether, decaffeinated versions of your favourite beverages may help reduce the severity of your symptoms.


Alongside being difficult to digest, alcohol leads to dehydration which has even further effects on the digestive system. Plus different alcoholic drinks can have varied effects on the body and therefore could trigger IBS symptoms; beer, for example, often contains gluten, and wines and mixers can contain high amounts of sugar.

Processed foods

Processed foods are simply foods that have been altered in any way during preparation; this can include canning, baking, freezing, and drying. Whilst not all processed foods are unhealthy, eating a lot of them can lead to serious health issues for anyone as they contain a high quantity of added salt, sugar, and fat. They also include additives and preservatives which can trigger IBS. Processed foods include:

  • Cereal
  • Crisps
  • Sausage rolls
  • Ready meals
  • Biscuits

Identifying Personal IBS Trigger Foods

You’ve narrowed down your IBS trigger food list, now how do you put the elimination diet into practice?

The elimination diet should begin with a cleanse of all trigger foods on your list. Keeping a food diary is recommended here to keep track of your progress, as well as charting symptoms. If you’re noticing that your symptoms are being alleviated, it means that the elimination diet is working.

Elimination diets should be a short term experiment, as many of the foods you are cutting out will be important for a healthy diet.

Once you’ve eliminated your trigger foods, it’s time to slowly reintroduce them. Take one food type at a time and eat a small amount to see if your symptoms resurge. If they don’t, try a larger amount the following day. Please note that symptoms could take a few days to appear after eating the trigger food.

Repeat the process for each trigger food and log your results in your food diary. Please note that you should only be sampling only one of your trigger foods at a time to keep the results accurate.

Looking to speed up the process? Read how our food sensitivity test can help IBS sufferers.

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