Low FODMAP Diet for Kids with IBS: A Gentler Approach

Updated 8 October 2026. Written and clinically reviewed by Bahee Van de Bor, RD, BCAPSc PGDipDiet, Specialist Paediatric Dietitian, former specialist dietitian at Great Ormond Street Hospital, with over 20 years of clinical experience in paediatric nutrition.

You’ve found a low FODMAP food list online. It’s long, it’s confusing, and half the foods your child actually eats are on the wrong side of it.

Maybe a friend tried it. Maybe an app made the low FODMAP diet for kids look simple. And you’re wondering whether to clear the cupboards and give it a go.

Before you do, I’d love to show you what FODMAPs are, why I don’t start children on the adult version of this diet, and what a gentler approach looks like instead.

What are FODMAPs?

FODMAPs are a group of carbohydrates that some children’s guts find harder to deal with.

The name stands for:

• Fermentable
• Oligosaccharides (fructans and GOS)
• Disaccharides (lactose)
• Monosaccharides (excess fructose)
• And
• Polyols (sugar alcohols such as sorbitol and mannitol)

Here’s what happens inside the gut. The small intestine absorbs FODMAPs poorly, so they pull extra water into the bowel. They then travel on to the large bowel, where gut bacteria ferment them and make gas.

In most children, none of this causes a problem. It’s normal digestion, and the bacteria doing the fermenting are often the ones we want to feed.

In a child with IBS, the gut is more sensitive to that stretch and gas. So the same amount of fermentation that another child wouldn’t notice can show up as tummy pain, bloating, wind, or a change in their poo.

The FODMAPs aren’t damaging the gut. The gut is reacting more strongly to them. That difference matters, and it’s why cutting them all out isn’t the answer.

What are the five FODMAP groups, and which foods contain them?

These are the five groups, and where each one turns up in a child’s everyday diet.

Portion size changes the picture.

A few slices of apple can sit comfortably, while a large glass of apple juice brings a big load of fructose and sorbitol in one go.

These examples show you which foods contain FODMAPs and why portions matter.

They are not a list of foods to remove from your child’s diet.

Many of these foods are also prebiotics.
Fructans and GOS in particular feed the beneficial bacteria in your child’s gut.
So knowing where FODMAPs are is useful.

It isn’t a reason to take them away.

Fruit and vegetables lower in FODMAPs

In normal portions, these are lower in FODMAPs:

• clementines
• carrots
• blueberries
• rock melon / cantaloupe melon
• green beans
• broccoli

Foods high in fructans or GOS and other FODMAPs include:

• Wheat and rye-based foods such as bread, pasta, and breakfast cereals (examples of fermentable oligosaccharides)
• Vegetables like onion, garlic, legumes (chickpeas and lentils), leeks
• Fruit such as apples, nectarine, watermelon
• Some nuts such as cashews and pistachios
• Some processed foods with added prebiotic fibre

What is lactose?

Lactose is the main type of carbohydrate found in milk and dairy products.  

Some children digest smaller quantities of it better than larger ones.

A lower lactose approach is not a dairy-free diet.

If lactose turns out to drive your child’s loose stools, they may still enjoy small amounts of milk, and most cheese and small quantities of yoghurt.

Which fruits are high in fructose?

Nearly all fruits and vegetables contain some fructose. The ones that matter here have more fructose than glucose, such as:

• apples
• pears
• dried fruit
• fruit juice

Vegetables with excess fructose, such as asparagus and artichokes, aren’t foods most children eat in large amounts.

Plenty of fruit stays on the menu, including firm bananas, berries and clementines. Your child can still reach their five a day.

Working with a paediatric dietitian keeps your child’s diet balanced, with enough energy and nutrients from every food group, even while you test a few foods.

What are polyols?

Polyols are sugar alcohols, such as sorbitol, mannitol and xylitol.

They occur naturally in apples, some pears, stone fruit, mushrooms and cauliflower.

Manufacturers also add them to sugar-free sweets, chewing gum and some “low sugar” products, so check the label for names ending in “-itol”.

If your child is in a supported trial, you’ll find ideas in 10 Delicious Low FODMAP Breakfast Recipes.

Why don’t I put children on a strict low FODMAP diet?

I’m a Monash University certified FODMAP dietitian, and Monash developed the low FODMAP diet. I still don’t start children on the strict version, and here is why.

The evidence in children is limited and mixed.

Rome V notes that some trials show a low FODMAP diet can ease symptoms in children with IBS.

But only a handful of trials exist, most are small, and several have design problems.

The most rigorous so far, a 2026 trial from Poland, found no clear difference in how many children responded after four weeks, although pain eased more on the low FODMAP diet.

It stopped early, so it was too small to give a firm answer.

In a small trial of children with functional abdominal pain, a low FODMAP diet did not significantly reduce pain, while standard dietary advice did.

Several of these trials delivered every meal to the family’s door, which is nothing like real life at home.

Most don’t report how the researchers taught the diet, so we can’t tell whether families had careful dietitian support or just a printed list.

And reintroduction matters. In a trial from Turkey, the diet stopped after two months with no reintroduction phase, and symptoms came back.

The current guideline doesn’t recommend it as routine treatment.

The 2025 European and North American guideline for IBS in children suggests against a strict low FODMAP diet, because the evidence isn’t strong enough to support it.

It also asks for particular caution with restrictive diets in children at risk of disordered eating.

Not every child reacts to every group.

In a study of children with IBS given fructans, about half had more tummy pain.

The other half didn’t.

And nothing about their symptoms beforehand could predict which children would react.

So a child might only struggle with one or two groups, and only above a certain amount.

Cutting out all five to find that out takes away far more than it needs to.

Can kids have IBS?

Yes. Doctors diagnose IBS in children using the Rome V criteria, from the age of six.

For at least two months, a child with IBS has:

• tummy pain on at least four days a month
• pain linked to their poo, so it comes on around going to the toilet, or with a change in how often they go or what their poo looks like
• pain as the main symptom, rather than the loose stools or constipation on their own
• no other condition that explains it, once the right checks are done

Some children mainly have loose stools, which is IBS with diarrhoea.

Some mainly have constipation, which is IBS with constipation.

And some swing between the two.

If your child’s tummy pain keeps coming back alongside changes in their poo, and nothing has explained it, IBS is worth raising with your GP.

In adults, a low FODMAP diet is a common treatment for IBS.

Children need an adapted, gentler version, used only after an assessment and alongside other changes.

If your child is at primary school and loose stools are the main problem, my post on loose stools in school-age children explains where IBS with diarrhoea fits.

If your child is a teenager, IBS in teenagers covers urgency, school and eating out.

What about toddler diarrhoea? If it isn’t IBS, what is it?

You may have read that toddler diarrhoea is really IBS starting early.

Officially, doctors don’t diagnose IBS before the age of six.

Rome V set that age because no studies have described IBS in younger children, not because it can’t happen. I believe that for some children, it does start earlier.

But for your toddler right now, the label matters less than the pattern.

Rome V calls frequent loose poos in a young child functional diarrhoea.

It means loose poos, usually without pain, starting anywhere from six months of age, in a child who is otherwise growing and thriving.

Younger children can still find some FODMAPs hard to absorb, especially the fructose and sorbitol in fruit juice and pouches.

In clinic, I’ve worked out which FODMAPs individual toddlers struggle with, and for some it has made a real difference. Whether that’s IBS starting early or something else, we don’t know yet.

Either way, the struggle is real, and it doesn’t need an IBS label to be worth sorting out.

Rome V recommends reducing juice and fructose in young children first, and keeps a low FODMAP diet as an option for older children.

For the full picture, read Toddler Diarrhoea: Why Does My Toddler Keep Having Loose Stools?

When might a gentle FODMAP approach help?

Here’s the part most parents don’t expect. For most children I see, the low FODMAP diet isn’t where we start.

First, a careful assessment.

I look at the pattern of pain and poo, what your child eats and drinks across a whole week, their growth, and what you’ve already tried. Often the answer is simpler than FODMAPs: fibre that’s too low or arriving all at once, not enough fluid, a lot of juice, or constipation hiding behind the symptoms.

Then, simpler changes first.

We sort those basics before anything else, one change at a time, so we can see what’s actually making the difference.

A gentle FODMAP trial only if we both agree it could help.

If the pattern still points to FODMAPs, I use a gentle approach, sometimes called “FODMAP gentle”.

Instead of removing every high FODMAP food, we swap only the foods that appear to be driving your child’s symptoms.

A few examples of what targeted can look like:

• Everyday wheat bread swapped for a traditional sourdough
• A daily glass of fruit juice swapped for a portion of whole fruit
• Cow’s milk swapped for lactose-free milk, keeping cheese and other dairy

These are illustrations, not a plan. The right swaps depend on your child, and they come out of the assessment.

It runs in three phases. Monash University describes the diet in three steps, and the same structure applies to the gentle version:

1. Elimination. A short trial of the targeted swaps. Rome V caps this at four to six weeks. I agree four weeks with the family.
2. Reintroduction. We bring foods back one group at a time, to find which ones matter and how much your child can comfortably have.
3. Personalisation. Your child goes back to the widest diet they can enjoy, limiting only what they need to, in the amounts they need to.

The goal at the end is a broader diet, not a narrower one.

What happens when a child follows the adult low FODMAP diet?

In clinic, I regularly see families who tried the adult version at home first. They followed every list to the letter. They read every label. And their child still wasn’t better, or felt worse.

Here’s what I see happen.

Symptoms can get worse, not better.

Cutting out fibre-rich bread, beans, fruit and vegetables all at once can leave a child more constipated and more uncomfortable than before.

Reintroduction stalls.

The first few weeks feel like progress, so it’s frightening to bring anything back. One food goes back in, a tummy ache follows (which may have nothing to do with that food), and it comes straight back out. Months later, the diet is narrower than when they started.

Nutrition gaps open up.

A child who has lost wheat, dairy, beans and half their fruit can fall short on energy, fibre, calcium, iron and other vitamins and minerals, at an age when they need them most for growth.

The gut bacteria lose their food.

Many FODMAPs are prebiotics, which means they feed the helpful bacteria in your child’s gut.

Bifidobacteria are one of those helpful groups.

They feed on some of the fermentable fibres in foods like wheat, beans and onions, and they help keep the gut environment healthy.

They are especially plentiful in babies.

And in one study, they made up a bigger share of the gut bacteria in healthy primary-school children than in the adults they were compared with.

In adults with IBS, short-term low FODMAP studies found lower levels of bifidobacteria.

A review of these trials found the same pattern across them, even though most lasted only three to four weeks. It didn’t find a clear change in the overall diversity of the gut bacteria.

In a small follow-up study, 18 adults who had gone through restriction, reintroduction and personalisation had similar bifidobacteria levels to their starting point a year later.

The authors suggest the full process may undo some of the effects of the restriction.

We don’t know what happens when a child stays on a strict diet for months without moving on to reintroduction. That uncertainty is one reason I keep any trial short, targeted and supported.

Eating becomes a worry.

Rome V strongly recommends a dietitian for any restriction diet in a child with IBS, because of the risk of avoidant and restrictive eating patterns developing.

A child who learns that food causes pain can start to fear it, and that is much harder to undo than a tummy ache.

None of this means the parent did anything wrong. Nobody designed the adult diet for a growing child.

When a paediatric dietitian leads a short, targeted trial, it looks very different.

The difference is the support, the short timeframe, and getting foods back in.

Can a low FODMAP diet help constipation?

Sometimes, but it’s rarely where I start with a constipated child. Many high FODMAP foods are also good sources of fibre, and taking them away can make constipation worse. I explain how the two fit together in Is the Low FODMAP Diet for Constipation Effective for Children?

If you’re not sure where to start

If your child has tummy pain, bloating or changes in their poo, and you’re wondering whether FODMAPs are part of the picture, the place to start is an assessment, not a food list.

Frequently Asked Questions

About the author

Bahee Van de Bor

RD, BCAPSc PGDipDiet, Specialist Paediatric Dietitian

Bahee is a specialist paediatric dietitian based at Harley Street, with over 20 years of experience including 12 years at Great Ormond Street Hospital. She is lead author of the forthcoming UK dietetic guidance for IBS and functional abdominal pain in children, and presented at ESPGHAN 2026.

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