Medication side effects: What should parents know?

When your child starts a new IBD medication, it’s normal to wonder about side effects.

You may find yourself watching closely for every headache, tummy ache or change in mood and wondering:

“Is this the medication?”

“Is this just part of their IBD?”

“Should I call the doctor?”

“Should we stop the medication?”

The answer isn’t always straightforward.

Children with Crohn’s disease or ulcerative colitis can experience symptoms from their IBD, infections, everyday childhood illnesses or their medication. Sometimes it can be difficult to tell the difference.

That’s why knowing what to watch for — and knowing who to contact — is so important.

💊 Every medication is different

There isn’t one list of side effects that applies to all IBD medications.

Different treatments work in different ways and have different potential side effects.

Your child’s treatment might include medicines such as:

• Aminosalicylates

• Corticosteroids

• Immunomodulators

• Biologics

• Biosimilars

• Other treatments recommended by their IBD team

The specific side effects, monitoring and warning signs depend on the medication your child is taking. Medication availability and prescribing information can also vary between countries.

Always use the information provided for your child’s specific medication and follow the advice of their healthcare team.

What is a side effect?

A side effect is an unwanted effect that can occur when taking a medication.

Some side effects may be:

• Mild

• Temporary

• More common when starting treatment

• Related to the dose

• Manageable without stopping treatment

Other side effects can be more serious and require medical attention.

Your child’s healthcare team should explain the important side effects associated with their medication and tell you which symptoms should prompt you to call.

🤔 Is it the medication or the IBD?

This can be one of the hardest questions for parents.

For example, your child may develop:

• Tummy pain

• Nausea

• Headaches

• Fatigue

• Changes in appetite

• Diarrhoea

But these symptoms can have many possible causes.

They could be related to:

• Active IBD

• A medication

• An infection

• Another illness

• Dehydration

• Poor sleep

• Stress

• Something unrelated to IBD

Don’t assume that every new symptom is a medication side effect.

If you’re unsure, tell your child’s IBD team what has changed.

🩺 Ask what is normal for your child’s medication

When your child starts a new medication, ask their healthcare team:

• What side effects are relatively common?

• Which symptoms should I expect?

• Which symptoms should make me call?

• Which symptoms require urgent medical attention?

• How long might mild side effects last?

• Does my child need blood tests?

• Are there medications or supplements they should avoid?

• Does the medication affect vaccinations?

• What should we do if my child develops an infection?

• What should we do if a dose is missed?

Writing down the answers can be helpful, especially when you’re dealing with several medications.

🌿 Steroids

Corticosteroids such as prednisolone or budesonide may be used to help bring an active IBD flare under control.

Steroids can have a range of side effects, particularly with higher doses or longer courses.

Depending on the medication and duration of treatment, these may include:

• Increased appetite

• Changes in mood or behaviour

• Difficulty sleeping

• Acne or skin changes

• Fluid retention

• Changes in blood pressure

• Changes in blood glucose

• Effects on growth with prolonged use

Your child’s healthcare team will consider the benefits and risks of steroid treatment and usually aims to use steroids for the shortest appropriate period.

Never stop steroid treatment suddenly unless your child’s healthcare team tells you to.

🧪 Immunomodulators

Medicines such as azathioprine, mercaptopurine and methotrexate can affect the immune system and may require regular blood monitoring.

Your child’s healthcare team may monitor blood counts and liver function, along with other tests depending on the medication.

Contact the healthcare team if your child develops symptoms that concern you, particularly:

• Fever

• Significant sore throat

• Unusual bruising or bleeding

• Marked weakness

• Yellowing of the skin or eyes

• Severe abdominal pain

• Other symptoms your healthcare team has specifically warned you about

Your child’s team will tell you which symptoms are particularly important for their medication.

💉 Biologics and biosimilars

Biologic medicines and biosimilars are used to treat many children with moderate-to-severe IBD.

Potential side effects vary depending on the specific medication.

Some children may experience reactions around an injection site or during an infusion.

Because these medicines can affect parts of the immune system, your child’s healthcare team may also monitor for infections and other specific risks.

If your child receives an infusion, the healthcare team will monitor them during and after treatment according to the medication and local protocol.

If your child uses an injectable medication at home, make sure you know:

• How to store it

• How to give it

• What to do if a dose is missed

• What injection-site reactions are expected

• Which symptoms require medical advice

💊 Aminosalicylates

Aminosalicylates, including medicines such as mesalazine, are commonly used in the treatment of some children with IBD, particularly ulcerative colitis.

Potential side effects depend on the specific medication.

If your child develops a new or unusual symptom after starting or changing treatment, let their healthcare team know.

They can determine whether it could be related to the medication or whether another explanation is more likely.

🦠 Infections and IBD medication

Some IBD treatments affect the immune system.

This can influence how your child’s body responds to certain infections.

Tell your child’s healthcare team if your child develops an infection or becomes unexpectedly unwell.

Don’t automatically stop their medication unless you’ve been given specific instructions to do so.

Some medications may have particular instructions during infections, so your child’s treatment plan matters.

💉 Vaccinations and medication

Vaccination advice can depend on your child’s medication.

Some treatments require special consideration around live vaccines, while other vaccines may be recommended as normal.

Vaccination schedules and recommendations also vary between countries.

Tell the healthcare professional giving the vaccine that your child has IBD and provide an up-to-date list of their medications.

If you’re unsure whether your child can have a particular vaccine, ask their IBD team first.

🧪 Why are blood tests important?

Some IBD medications require regular blood monitoring.

Blood tests can help your healthcare team check for medication-related problems before your child develops noticeable symptoms.

Depending on the medication, monitoring may include:

• Full blood count

• Liver function

• Kidney function

• Inflammatory markers

• Nutritional markers

• Other medication-specific tests

The frequency of testing varies according to the medication, your child’s age, their health and local treatment guidelines.

If you aren’t sure why your child is having a particular blood test, ask.

📞 When should I call the IBD team?

Contact your child’s IBD team if you notice a new or concerning symptom after starting or changing medication.

You should also contact them if:

• A side effect is getting worse

• Your child is struggling to take the medication

• Your child develops a significant infection

• You are worried about a medication reaction

• You are unsure whether to give the next dose

• Your child has missed several doses

• Your child develops new symptoms that could be related to their treatment

• You are considering stopping the medication

You don’t need to work out whether the medication is definitely responsible. Tell the team what happened and let them help you decide what to do.

🚨 When does a side effect need urgent medical attention?

Some symptoms can indicate a serious reaction or another medical problem.

Seek urgent medical care if your child develops symptoms such as:

• Difficulty breathing

• Swelling of the face, lips, tongue or throat

• Fainting or severe dizziness

• Severe or rapidly worsening abdominal pain

• Heavy bleeding

• Repeated vomiting with inability to keep fluids down

• Severe dehydration

• Significant confusion or difficulty staying awake

• A severe allergic-type reaction

• A very high or persistent fever with your child appearing seriously unwell

If your child is seriously unwell or you believe they are experiencing an emergency, seek emergency medical care rather than waiting for the IBD team to respond.

❌ Should I stop the medication?

This is one of the most important questions.

Don’t stop your child’s IBD medication without medical advice unless your healthcare team has specifically given you instructions to do so in a particular situation.

Stopping treatment suddenly can sometimes cause problems, and the risks of stopping vary between medications.

If you think your child is having a side effect, contact their IBD team or pharmacist and explain exactly what has happened.

They may advise you to continue, pause, change or stop the medication — depending on the situation.

📝 Keep a medication and symptom record

If you’re concerned about a possible side effect, write down:

Medication

Dose

Date started

When the symptom began

What happened

How long it lasted

Any other symptoms

Any other medication taken

This can help your healthcare team work out whether there may be a connection.

It can also be useful to record when medication doses are taken, particularly if symptoms appear at a particular time afterwards.

👧 Help your child describe what they’re feeling

Children don’t always describe side effects in medical terms.

Instead of asking:

“Are you having any side effects?”

try asking:

• “How does your tummy feel?”

• “Have you noticed anything different?”

• “Do you feel different after taking your medicine?”

• “Have you felt dizzy or sick?”

• “Does anything hurt?”

• “Is there anything you’re worried about?”

As your child gets older, encourage them to speak directly with their healthcare team. Learning to recognise and report medication side effects is an important part of becoming independent with IBD.

🌍 Medication advice varies between countries

IBD medication availability, approved uses, age restrictions, monitoring requirements and prescribing guidelines can differ between countries.

The same medication may also have different brand names or formulations.

For this reason, online information should be treated as general education rather than instructions for your individual child.

If you’re unsure about a side effect, use the medication information provided in your country and contact your child’s local healthcare team or pharmacist.

❤️ Don’t be afraid to ask

It is completely reasonable to ask questions about your child’s medication. You might worry that you’re being difficult or asking too many questions. You’re not.

Understanding your child’s treatment helps you feel more confident and helps you know what to look out for.

Ask:

“What should I expect?”

“What should worry me?”

“Who should I call?”

“What should I do if this happens?”

Those four questions can give you a much clearer plan.

Medication should feel like a partnership

Your child’s IBD medication is an important part of managing their Crohn’s disease or ulcerative colitis, but you don’t have to navigate it alone.

Your child’s gastroenterologist, IBD nurse, pharmacist and other healthcare professionals can help you understand what each medication does, what to watch for and what to do if something changes.

You don’t need to know every possible side effect. You just need to know which warning signs matter for your child’s specific treatment — and who to call when you’re unsure.