12 foods to avoid with IBS

24th January 2020

Irritable bowel syndrome (IBS) is a chronic medical condition that causes a person to experience stomach upsets, particularly in relation to certain foods. Symptoms vary but largely involve diarrhoea, constipation, gas, bloating and stomach cramps and these can be managed and reduced with effective IBS medications.

Every person is different so it’s important to learn your own illness and patterns (perhaps by keeping a diary). But as a general rule of thumb, these are some foods that it’s wise to avoid.


Caffeine is a stimulant, and while the main perception is that it stimulates your brain, it also stimulates your intestines. This can cause diarrhoea, so when IBS sufferers need a pick-me-up, you’re better off reaching for a small snack than a coffee.


The way that the body digests alcohol, paired with the fact that it’s dehydrating and affects liver function, can affect the digestion of a healthy-bodied person. So for someone with IBS, the effects of a boozy night out can be troublesome.

If you are drinking, try to make wise choices such as a spirit with a sugar-free mixer.

Fried food

Foods with high fat content (such as anything that’s been deep fried) can be harsh on the digestive system of people with IBS. Because frying food can make it harder to digest, consider grilling or baking foods where you can and only eat fried food in moderation.


A lot of people with IBS are lactose intolerant, which means that eating dairy (milk, cheese, yogurt etc) can worsen symptoms and cause diarrhoea. Thankfully, it’s easy to find lactose-free alternatives of most (if not all) dairy foods, so you won’t need to feel like you’re missing out.


Most people know that chocolate is high in sugar, but not everyone realises its concentration of caffeine. Pair the two together and you’ll find that chocolate causes constipation for a lot of IBS sufferers. However, a lot find that vegan chocolate is more tolerable.

Sugar-free sweeteners

A diet high in sugar is not good for anyone, let alone people with IBS. But be careful of products that are labelled as ‘sugar-free’. These foods usually contain sweeteners instead, which are harder for the body to absorb.

Garlic and onions

These two versatile vegetables are the base of most great recipes and are wonderful at adding flavour to your food. However, they can be difficult for your intestines to break down which can cause trapped wind and painful cramping. This is usually worse with the raw versions of garlic and onion but the cooked versions can still be triggers for those with IBS.


Gluten is a protein that is present in a number of different grains (like wheat, rye and barley), and a lot of IBS sufferers are also gluten intolerant. Luckily, there are now so many gluten-free options available that this shouldn’t restrict your diet too much, but just be careful to check food labels if you find that gluten is a trigger for you.

Broccoli and cauliflower

These tree-shaped vegetables are not the easiest to digest, even for people without IBS. So if someone with IBS eats them, that tricky digestion can result in trapped wind and constipation. Grating these vegetables can help, but a lot find that cutting them out altogether is best.

Insoluble fibre

Fibre can be broken down into soluble and insoluble categories, with the latter causing (or worsening) diarrhoea in a lot of IBS sufferers. However, you shouldn’t cut fibre out completely, as it adds healthy bulk to your diet and helps to regulate digestion.

Aim for soluble fibres. This is present in grains like oatmeal and barley, fruits like berries, oranges and grapefruit and vegetables like carrots and parsnips.


Beans and legumes are a great source of protein and are a leading staple for people following a plant-based or vegan diet. However, they can cause gas and bloating, which can lead to painful cramps.

Fizzy drinks

This one is a simple in-out phenomenon. Fizzy drinks are carbonated with air and as you drink them, you’re also taking in all that extra gas. And since what goes in, must come out, these drinks can cause bloating, trapped wind and constipation.

FODMAP foods

For people with IBS, daily eating doesn’t have to be a minefield. Experts recommend following a low FODMAP diet in order to avoid triggering symptoms.

FODMAP (Fermentable Oligosaccharides, Disaccharides, Monosaccharides, and Polyols) gets its name from a number of different carbohydrates, as the diet focuses on eating long-chain carbohydrates that your body will be able to absorb and digest properly.

This doesn’t mean you can’t eat fruits, vegetables, grains, proteins and anything else that you enjoy. It’s simply about making smarter choices in order to improve symptoms. And if changing your diet doesn’t help, then IBS medications should be able to.