Crohn’s or ulcerative colitis: What’s the difference?

If your child has recently been diagnosed with IBD, you may be wondering what the difference is between Crohn’s disease and ulcerative colitis. Here’s a simple guide for parents.

If you’ve been told that your child has inflammatory bowel disease (IBD), you may have heard the words Crohn’s disease and ulcerative colitis (UC).

But what actually makes them different?

Both are types of IBD. Both involve inflammation. Both can cause symptoms such as abdominal pain, diarrhoea and fatigue. And both can affect a child’s everyday life.

The biggest difference is where the inflammation occurs and how it affects the digestive tract.

Understanding the basics can make medical appointments and conversations with your child’s IBD team a little easier.

🩺 First, what is IBD?

IBD stands for inflammatory bowel disease.

It is a group of conditions involving ongoing inflammation in the digestive tract.

The two main types are:

• Crohn’s disease

• Ulcerative colitis

There is also a third category called IBD-unclassified (IBD-U), which may be used when doctors cannot clearly determine whether a child’s condition is Crohn’s disease or ulcerative colitis.

IBD is different from irritable bowel syndrome (IBS). IBS can cause digestive symptoms but does not cause the same type of intestinal inflammation seen in IBD.

🔵 What is Crohn’s disease?

Crohn’s disease can cause inflammation anywhere along the digestive tract.

This means it can affect areas from the mouth all the way through to the anus.

In children, Crohn’s disease commonly affects the:

• Small intestine

• Large intestine

• Area where the small and large intestines meet

But every child is different.

Crohn’s inflammation can also occur in patches, meaning there can be areas of inflamed bowel with areas of healthy bowel in between.

The inflammation can affect deeper layers of the bowel wall, which is one of the features that distinguishes Crohn’s disease from ulcerative colitis.

🟠 What is ulcerative colitis?

Ulcerative colitis causes inflammation in the large intestine, or colon.

It affects the inner lining of the colon and usually begins in the rectum, extending upwards to varying degrees.

Unlike Crohn’s disease, ulcerative colitis does not affect the entire digestive tract.

The inflammation is generally continuous rather than occurring in separate patches.

Some children have inflammation throughout their colon, while others have inflammation affecting only part of it.

🚽 Do the symptoms look different?

There can be a lot of overlap between Crohn’s disease and ulcerative colitis.

Both can cause:

• Diarrhoea

• Abdominal pain

• Fatigue

• Reduced appetite

• Weight loss

• Poor weight gain

• Blood in the stool

• Urgency to use the toilet

• Needing to use the toilet frequently

However, some symptoms can be more common depending on which type of IBD your child has and where the inflammation is located.

For example, blood in the stool and urgency are common symptoms of ulcerative colitis, while Crohn’s disease can cause symptoms related to inflammation in the small intestine, such as abdominal pain, diarrhoea and difficulty absorbing nutrients.

But symptoms alone generally aren’t enough to determine whether a child has Crohn’s disease or ulcerative colitis.

That’s why doctors use a combination of medical history, blood tests, stool tests, endoscopy, biopsies and imaging.

🧪 How do doctors tell the difference?

Diagnosing Crohn’s disease or ulcerative colitis isn’t usually based on one test.

Your child’s gastroenterologist will look at the whole picture.

This may include:

Blood tests

Blood tests can provide information about inflammation, anaemia, iron levels and your child’s overall health.

Stool tests

Tests such as faecal calprotectin can provide information about inflammation in the intestines.

Stool tests may also help doctors rule out infections that can cause similar symptoms.

Endoscopy and colonoscopy

Doctors can look directly at the digestive tract and take small tissue samples called biopsies.

The appearance of the bowel and the biopsy results can provide important information about the type and extent of inflammation.

Imaging

Some children may need imaging such as an MRI or MR enterography to examine parts of the digestive tract, particularly the small intestine.

🧩 What if the doctors aren’t sure?

Sometimes your child’s symptoms, test results and biopsies don’t clearly fit Crohn’s disease or ulcerative colitis.

Your child may then be diagnosed with IBD-unclassified (IBD-U).

This can feel confusing for parents.

You might think:

“If they know it’s IBD, why don’t they know which type?”

IBD can be complicated, particularly in children.

As your child’s condition is monitored over time, their doctors may gain a clearer understanding of the pattern of their disease.

The diagnosis can sometimes change as more information becomes available.

💊 Is the treatment different?

There can be differences in how Crohn’s disease and ulcerative colitis are treated.

However, there is also a lot of overlap.

Treatment may include medicines such as:

• Aminosalicylates

• Corticosteroids

• Immunomodulators

• Biologic medicines

• Other targeted treatments

Some children with Crohn’s disease may also receive exclusive enteral nutrition (EEN) as part of their treatment.

Your child’s treatment will depend on their individual situation, including the type and location of their IBD, how active the disease is, their age, growth and previous response to treatment.

There is no single treatment plan that works for every child.

📈 What about growth and puberty?

Growth is particularly important in children with IBD.

Active inflammation, reduced appetite and nutritional problems can affect:

• Weight gain

• Height

• Growth

• Puberty

• Energy levels

• Nutritional status

This is why your child’s gastroenterology team may regularly monitor their height and weight.

If you’re concerned that your child isn’t growing as expected, bring it up with their IBD team.

🦴 Can both types cause problems outside the bowel?

Yes.

IBD can affect parts of the body outside the digestive tract. These are called extraintestinal manifestations.

Children with Crohn’s disease or ulcerative colitis may experience problems involving areas such as:

• Joints

• Skin

• Eyes

• Liver and bile ducts

Not every child will experience these problems.

If your child develops new symptoms outside the digestive system, let their healthcare team know.

🔥 Can both Crohn’s disease and ulcerative colitis flare?

Yes.

Both conditions can have periods when inflammation becomes more active.

These are commonly called flares.

A flare may cause symptoms such as:

• Increased diarrhoea

• Abdominal pain

• Blood or mucus in the stool

• Urgency

• Fatigue

• Reduced appetite

• Weight loss

• Fever

The aim of treatment is to control inflammation and help your child achieve and maintain remission.

❤️ Does one type of IBD mean a different future?

It’s understandable to wonder what your child’s diagnosis means for their future.

But there isn’t a simple answer.

Crohn’s disease and ulcerative colitis can both vary considerably from child to child.

Some children have relatively mild disease, while others need more intensive treatment.

The location and severity of inflammation, response to treatment, growth, nutrition and other factors all contribute to how a child’s IBD is managed.

Your child’s diagnosis is not a prediction of exactly what their future will look like.

Their gastroenterology team will monitor how their disease behaves and adjust treatment as needed.

❓ Questions to ask your child’s gastroenterologist

If you’re still trying to understand your child’s diagnosis, you could ask:

• Does my child have Crohn’s disease or ulcerative colitis?

• Where exactly is the inflammation?

• How active is the inflammation?

• What did the biopsies show?

• What did the colonoscopy or endoscopy show?

• Does my child need an MRI or other imaging?

• What treatment do you recommend and why?

• How will we know whether treatment is working?

• How will you monitor my child’s growth?

• What symptoms should make us contact the IBD team?

• What should we do if we think our child is having a flare?

• Could my child’s diagnosis change as they get older?

Don’t be afraid to ask your child’s gastroenterologist to explain something again.

You don’t need to understand every medical term immediately.

💛 The most important thing to remember

Crohn’s disease and ulcerative colitis are different conditions, but they are both forms of IBD.

The differences can help doctors decide how to investigate and treat your child’s condition, but your child’s diagnosis is only one part of their story.

Your child is still your child.

They can still go to school, play sport, spend time with friends, travel, have sleepovers and make plans for the future.

There may be times when IBD gets in the way, but with the right medical care and support, children with IBD can continue to grow, learn and take part in the things that matter to them.

If you’re new to IBD, take it one step at a time. You don’t need to understand everything today.