The Trigger Foods to Avoid with IBS, and Low FODMAP Alternatives

To dodge the diarrhea, constipation, and other irksome abdominal symptoms associated with irritable bowel syndrome (IBS), you’ll need to be aware of your ‘IBS trigger foods’.

What are IBS trigger foods?

Well, we’ll have to cop-out and say ‘it depends’.

…Fine, we’ll tell you a bit more. While your IBS trigger foods are determined by your unique food sensitivities – consult your dietitian for tests – there are some universally identified triggers that tend to lead to digestive problems more than others.

The following are foods to avoid with IBS – we recommend eliminating all or some of these foods completely, and then re-introducing them into your diet slowly, one at a time, to gauge what may be aggravating your IBS symptoms.

High FODMAP Fruits: Apples, Pears, and Watermelon


An apple a day keeps the doctor away…but won’t keep that diarrhea at bay.

From Granny Smiths to Pink Ladies, a single apple (65g) serving is flagged as high FODMAP by Monash University’s FODMAP Diet experts. Apples contain elevated levels of fructose and polyol-sorbitol, both of which intensify IBS symptoms and trigger diarrhea. The excess fiber apples are famous for, especially in their skins, can also irritate your gut.

Pears are equal opportunity diarrhea machines. No matter the type of pear - white, yellow, nashi, clingstone, packham, prickly – it’ll aggravate your IBS symptoms. Similar to apples, pears contain high levels of the FODMAP polyol-sorbitol at a single serving size (145g). And like apples, their high fiber means a high likelihood of extended bathroom time.

Everyone’s favourite BBQ treat, watermelon is arguably the most refreshing fruit to bite into – and arguably the worst for your IBS food sensitivities.

This IBS trigger food has high levels of oligos, fructose, and polyols per single slice (286g). For those keeping track at home, that’s three of the four major FODMAPs that trigger IBS symptoms. There are less troublesome ways to hydrate yourself in the summer, albeit less delicious and satisfying.

Low FODMAP Alternatives (with Recipes!):

Carbonated Drinks

Carbonated Drinks

Carbonated beverages can hamper your IBS management. As we all know, carbonation contributes to gas buildup in our abdominal regions, and if it can’t get passed, it accumulates. This leads to bloating and discomfort, including sharp pains in your midsection.

Carbonated drinks usually contain some levels of caffeine, which also contributes to IBS problems. Caffeine is known to increase stomach acid production, again leading to abdominal discomfort. Caffeinated drinks also worsen constipation symptoms, playing a key part in dehydration.

Finally, the sweeteners commonly found in carbonated drinks can exacerbate IBS symptoms due to their laxative effects.

Low FODMAP Alternatives:

High FODMAP Dairy Products

Dairy Products

Good news, everyone: A low FODMAP diet doesn’t have to be a dairy-free one!

The bad news is most dairy products containing lactose – or the ‘D’ in the FODMAP acronym – are classified high FODMAP by Monash University’s food experts.

Intolerance for lactose is common in people with gastrointestinal issues like coeliac disease and IBS. Lactose intolerance can cause bloating, abdominal pain, cramps, gas, diarrhea, and even vomiting.

There are too many high FODMAP dairy products to list – including all the creams, milks, yogurts, custards, ice creams, cheeses, and more – so refer to your Monash University Low FODMAP App for nutritional guidelines specific to your food intolerances.

But back to the good news – here are some dairy products that ARE Low FODMAP:

Broccoli and Cauliflower

Your gut and intestines want to hide that broccoli and cauliflower in the nearest potted plant just like your shrewd kids do.

Broccoli does come with a caveat, however: certain parts of the veggie are high FODMAP, while others are low. For example, one serving of the whole vegetable, both head and stalk, is considered low FODMAP. But the stalks on their own are considered high FODMAP, and heads on their own are considered low.

When it comes to broccolini though, it’s the reverse: stalks=low FODMAP; heads=high FODMAP; whole=high FODMAP.

Due to the high content of polyol-mannitol in broccoli’s cousin, the cauliflower, it’s been classified high FODMAP by Monash University.

Low FODMAP Vegetable Alternatives (with Recipes!):

Better Food Choices with a Low FODMAP Diet

Now that you know some of the foods to avoid with IBS, we’ll leave you with some general food tips as you continue your path along a Low FODMAP diet.

For an extensive list of high FODMAP foods, check out our dedicated high FODMAP foods list page here. And for the low FODMAP alternative, visit our low FODMAP foods list!