What causes IBD in children?

Why does my child have IBD? Did I do something wrong? Is it something they ate? Could I have prevented it?

These are incredibly common questions for parents after a child is diagnosed with inflammatory bowel disease (IBD).

The short answer is:

We don’t know exactly what causes IBD.

What we do know is that IBD is thought to develop from a combination of genetic, immune system, environmental and other factors.

And most importantly, you did not cause your child’s IBD.

🧩 IBD is not caused by one thing

IBD is a complex condition.

It isn’t as simple as one food, one infection, one stressful event or one gene causing the disease.

Researchers believe IBD develops when several factors interact in a person who is genetically susceptible to the condition.

These factors can include:

• Genetics

• The immune system

• The gut microbiome

• Environmental factors

• Other factors that researchers are still trying to understand

This is sometimes described as the “multifactorial” nature of IBD.

🧬 Does IBD run in families?

Genetics can play a role in IBD.

Children who have a close relative with Crohn’s disease or ulcerative colitis have a higher risk of developing IBD than children without a family history.

But having a family member with IBD doesn’t mean a child will definitely develop it.

And many children diagnosed with IBD don’t have a parent or close family member with the condition.

Scientists have identified many genetic variations associated with IBD, but genetics alone don’t explain why someone develops the disease.

Think of genetics as one piece of the puzzle, rather than the whole answer.

🛡️ What does the immune system have to do with IBD?

Our immune system protects us from things that can make us sick.

With IBD, the immune system becomes involved in an abnormal or ongoing inflammatory response in the digestive tract.

Instead of inflammation switching off normally, the immune system can continue to drive inflammation.

This can damage the lining of the digestive tract and lead to the symptoms associated with Crohn’s disease and ulcerative colitis.

Researchers are still working to understand exactly why this happens.

🦠 What about the gut microbiome?

Your child’s digestive tract contains trillions of microorganisms, including bacteria, viruses and fungi.

Together, these microorganisms are known as the gut microbiome.

The microbiome plays an important role in digestion, immunity and the health of the intestinal lining.

Research has found differences in the gut microbiome of people with IBD compared with people without IBD.

However, researchers are still trying to determine whether these changes help cause IBD, result from IBD or are influenced by treatment, diet or inflammation.

So, while the gut microbiome appears to be important, we don’t currently have a simple answer such as:

“This particular bacteria caused my child’s IBD.”

🌍 Can environmental factors play a role?

Researchers believe that environmental factors may contribute to the development of IBD.

These may include things such as:

• Where someone lives

• Diet and nutrition

• Exposure to infections

• Antibiotic exposure

• Smoking and second-hand smoke

• Other aspects of the environment

But this does not mean that one of these things caused your child’s IBD.

IBD is much more complicated than that.

Scientists are still investigating which environmental factors matter, how they interact with genetics and the immune system, and why IBD is becoming more common in many parts of the world.

🍔 Did food cause my child’s IBD?

No.

There is no evidence that a particular food or normal childhood diet simply causes a child to develop IBD.

This is an important one for parents because food can become a source of guilt after diagnosis.

You may find yourself thinking:

“Did we feed them the wrong foods?”

“Should I have noticed something earlier?”

“Could I have prevented this?”

Please don’t blame yourself.

IBD is not caused by parents giving their child the wrong foods.

Once a child has IBD, however, food and nutrition can become important parts of managing their health.

Your child’s nutritional needs may change depending on whether their disease is active, whether they’re growing normally and what treatment they are receiving.

A paediatric IBD dietitian can help you navigate this without unnecessary food restriction.

😟 Did stress cause my child’s IBD?

Stress does not cause IBD.

However, stress can affect how a child feels and may make some symptoms feel worse.

Children with IBD may also notice that symptoms are harder to manage during stressful periods.

This can create a confusing cycle:

Stress → symptoms feel worse → more worry → more stress

It’s important to distinguish this from saying that stress caused the underlying IBD.

Your child’s IBD is not their fault, and it isn’t caused by them being worried, anxious or stressed.

🦠 Did an infection cause it?

Some infections can cause symptoms that look very similar to IBD, including diarrhoea, abdominal pain and blood in the stool.

This is one reason doctors often perform stool tests when investigating a child with possible IBD.

Researchers are also investigating whether certain infections or changes in the immune response to infections could contribute to IBD developing in genetically susceptible people.

But there is no single infection that can be identified as the cause of IBD in most children.

💊 Did antibiotics cause my child’s IBD?

You may read about research linking antibiotic exposure with IBD.

Antibiotics can change the bacteria living in the gut, and researchers are investigating whether changes to the gut microbiome may influence IBD risk.

However, this does not mean that giving your child antibiotics caused their IBD.

Sometimes antibiotics are necessary to treat infections, and your child’s doctor will weigh up the benefits and risks of treatment.

Don’t avoid medically necessary antibiotics because you are worried about IBD.

💉 Did a vaccine cause IBD?

There is no good evidence that routine childhood vaccination causes Crohn’s disease or ulcerative colitis.

If you have concerns about a particular vaccine or your child’s medical history, talk to their doctor.

🧠 Can IBD be caused by something that happened during pregnancy or childhood?

Parents often look back after a diagnosis and wonder whether something happened earlier that could have caused the disease.

Researchers have investigated many possible early-life influences, including:

• Pregnancy

• Birth

• Breastfeeding

• Early childhood infections

• Antibiotic exposure

• Diet

• Environmental exposures

Research in these areas is ongoing.

There is currently no simple list of childhood experiences that can be blamed for a child’s IBD.

🧬 Why did my child get IBD if nobody else in our family has it?

This is a very common question.

Although genetics can increase the risk of IBD, most children with IBD do not necessarily have an immediate family member with IBD.

A child can have genetic susceptibility without anyone else in the family having been diagnosed.

Other factors may also contribute.

Researchers are still working to understand exactly how these factors interact.

❌ Things that did not cause your child’s IBD

It is worth saying this clearly.

Your child’s IBD was not caused by you being a bad parent.

It wasn’t caused by:

• You not noticing symptoms sooner

• Your child eating the “wrong” foods

• Your child being stressed about school

• Your child being anxious

• Your parenting style

• Your child not exercising enough

• Something you did or didn’t do during pregnancy

• You failing to prevent it

IBD is a complex disease, and in most cases there isn’t one thing that a parent can point to and say:

“That’s what caused it.”

🔎 So, what actually causes IBD?

The best answer we currently have is that IBD probably develops when multiple factors interact.

A simplified way of thinking about it is:

🧬 Genetics

Your child may have genetic factors that make them more susceptible to IBD.

🛡️ Immune system

Their immune system may respond abnormally to things in the digestive tract.

🦠 Gut microbiome

The microorganisms living in their digestive tract may influence how the immune system and gut interact.

🌍 Environment

Environmental factors may contribute to whether IBD develops in someone who is already susceptible.

❓ Factors we haven’t discovered yet

There is still a lot researchers don’t understand.

It may be the interaction between these factors — rather than one single cause — that leads to IBD.

❤️ What can I do now?

Once your child has been diagnosed with IBD, it’s understandable to want to know what you can do to stop it happening again.

But you don’t need to spend your time searching for the one thing that caused it.

Instead, focus on what you can control now:

• Helping your child take their medication as prescribed

• Attending gastroenterology appointments

• Monitoring symptoms

• Supporting healthy growth and nutrition

• Working with your child’s healthcare team

• Supporting their emotional wellbeing

• Helping them stay involved in school, sport and everyday life

• Learning about their particular type of IBD

There is no perfect parent checklist that could have prevented your child’s IBD.

🌱 Research is still looking for answers

IBD research is constantly evolving.

Scientists are studying genetics, the immune system, the gut microbiome, environmental factors and the interactions between them.

The more researchers learn, the better we may understand why IBD develops and how it can be prevented or treated in the future.

For now, there is still no single known cause of Crohn’s disease or ulcerative colitis.

And that’s important to remember when you find yourself asking:

“Why my child?”

Sometimes there simply isn’t an answer yet.

What we do know is that your child didn’t cause their IBD, and neither did you.

Your focus now can be on helping your child feel well, supporting their treatment and making sure they know that IBD is something they have — not who they are.