What do all these IBD terms mean?

Here’s a simple guide to the words and medical terms you may hear after your child is diagnosed with Crohn’s disease or ulcerative colitis.

When your child is diagnosed with inflammatory bowel disease (IBD), it can feel like you’re suddenly learning a whole new language.

Your gastroenterologist might talk about remission, inflammation, faecal calprotectin, biologics, mucosal healing and biomarkers — all while you’re trying to remember what medication your child needs to take.

It can be a lot.

You don’t need to become an IBD expert overnight. This guide explains some of the most common IBD terms for parents in simple language.

🩺 The basics

IBD

Inflammatory bowel disease (IBD) is a group of conditions that cause ongoing inflammation in the digestive tract.

The two main types are Crohn’s disease and ulcerative colitis.

Crohn’s disease

Crohn’s disease is a type of IBD that can cause inflammation anywhere along the digestive tract, from the mouth to the anus.

The inflammation can affect different layers of the bowel and may occur in patches, with healthy areas between inflamed areas.

Ulcerative colitis

Ulcerative colitis (UC) is a type of IBD that causes inflammation in the lining of the large intestine, or colon.

It usually starts in the rectum and can extend further into the colon.

IBD-unclassified

Sometimes doctors cannot clearly determine whether a child’s IBD is Crohn’s disease or ulcerative colitis.

In these cases, they may use the term IBD-unclassified (IBD-U).

This doesn’t mean that your child’s symptoms aren’t real or that doctors don’t know what they’re doing. It simply means the features don’t clearly fit into one category at that time.

Paediatric IBD

Paediatric IBD simply means IBD in children and teenagers.

Children with IBD have some different considerations from adults, including growth, puberty, nutrition, school and development.

🔥 Understanding inflammation and flares

Inflammation

Inflammation is the body’s response to injury, irritation or disease.

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

Your child may have inflammation even when they don’t have obvious symptoms.

Active disease

This means that there are signs of active inflammation or IBD activity.

Your child’s doctor may use symptoms, blood tests, stool tests, scans or endoscopy to assess how active the disease is.

Flare

An IBD flare is a period when the disease becomes more active and symptoms may return or become worse.

Symptoms can include diarrhoea, abdominal pain, blood or mucus in the stool, urgency, fatigue, reduced appetite or weight loss.

A flare can look different from one child to another.

Remission

Remission means that the IBD is under control and there are few or no signs of active disease.

Your doctor may talk about different types of remission depending on your child’s symptoms and test results.

Remission doesn’t necessarily mean that IBD has disappeared permanently. Your child will still need ongoing monitoring.

Relapse

Relapse is another term that may be used when IBD becomes active again after a period of improvement or remission.

You may hear your doctor use flare and relapse in slightly different ways.

🧪 Tests and results

Faecal calprotectin

This is a stool test that can help detect inflammation in the intestines.

You may hear it called calprotectin or FC.

Doctors can use faecal calprotectin to help assess intestinal inflammation and monitor how your child’s IBD is responding to treatment.

CRP

CRP stands for C-reactive protein.

It is a blood test that can be used as a marker of inflammation in the body.

A raised CRP can indicate inflammation, although CRP isn’t specific to IBD and can be affected by other things, including infections.

ESR

ESR stands for erythrocyte sedimentation rate.

It is another blood test that can provide information about inflammation.

Your child’s doctor may look at ESR alongside other blood tests, symptoms and test results.

FBC or CBC

FBC stands for full blood count.

You may also see CBC, which stands for complete blood count.

This blood test looks at different types of blood cells and can help doctors identify things such as anaemia or changes associated with infection or inflammation.

Haemoglobin

Haemoglobin is a protein in red blood cells that carries oxygen around the body.

Low haemoglobin can be a sign of anaemia.

Ferritin

Ferritin is a protein that stores iron.

A ferritin blood test can help doctors assess your child’s iron stores.

Iron deficiency and iron-deficiency anaemia can occur in children with IBD.

Biomarker

A biomarker is something measurable in the body that can provide information about a disease or how it is behaving.

In IBD, examples include blood markers such as CRP and stool markers such as faecal calprotectin.

🔬 Scans and procedures

Endoscopy

An endoscopy allows doctors to look inside parts of the digestive tract using a flexible camera.

An upper endoscopy, also called a gastroscopy, can examine areas including the oesophagus, stomach and upper part of the small intestine.

Colonoscopy

A colonoscopy allows doctors to examine the inside of the large intestine and usually the end of the small intestine.

Small tissue samples called biopsies can be taken during the procedure.

Biopsy

A biopsy is a small sample of tissue taken during a procedure.

A pathologist examines the tissue under a microscope to look for signs of inflammation or other changes.

MRI

MRI stands for magnetic resonance imaging.

It uses magnetic fields and radio waves to create detailed images of parts of the body.

An MR enterography (MRE) is a type of MRI that can provide detailed images of the small intestine and surrounding areas.

Imaging

Imaging is a general term for tests that create pictures of parts of the body.

Depending on the situation, your child may have an MRI, ultrasound, X-ray or another type of imaging.

💊 IBD treatment terms

Medication

Medication is used to help control inflammation, treat symptoms and maintain remission.

There are several different types of medicines used to treat IBD.

Aminosalicylates

Aminosalicylates, sometimes called 5-ASAs, are medicines that help reduce inflammation.

Mesalazine is one example.

Steroids

Corticosteroids, often simply called steroids, can be used to reduce inflammation during an IBD flare.

They are generally used for shorter periods rather than as a long-term maintenance treatment.

Immunomodulator

An immunomodulator is a medication that changes or modifies the activity of the immune system.

Some immunomodulators are used as part of IBD treatment.

Biologic

A biologic is a type of medicine made using living cells or biological processes.

Biologic medicines target specific parts of the immune or inflammatory response involved in IBD.

Biosimilar

A biosimilar is a biological medicine that is highly similar to an existing biologic medicine.

Your child’s doctor or pharmacist can explain whether a biosimilar is being used and what that means for your child’s treatment.

Maintenance treatment

Maintenance treatment is treatment used to help keep IBD under control and maintain remission.

It is different from treatment used specifically to bring an active flare under control.

Induction

Induction treatment is the treatment used to bring active IBD under control and achieve remission.

Dose

The dose is the amount of medication your child needs to take.

Your child’s dose may depend on factors such as their weight, age, condition and the medication being used.

Side effect

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

Not everyone experiences the same side effects.

If you’re concerned about a medication your child is taking, speak with their healthcare team rather than stopping it without medical advice.

🥗 Nutrition and growth

Enteral nutrition

Enteral nutrition is nutrition delivered through the digestive system.

In some children with Crohn’s disease, a special liquid nutritional formula may be used as part of treatment.

Your child’s gastroenterologist and dietitian can explain whether this is appropriate for your child.

Exclusive enteral nutrition

Exclusive enteral nutrition (EEN) means receiving nutrition from a prescribed liquid formula without eating regular food for a set period.

EEN may be used as a treatment for some children with Crohn’s disease.

Malnutrition

Malnutrition means that the body isn’t getting enough of the nutrients or energy it needs.

Children with active IBD can sometimes be at risk of nutritional deficiencies or difficulty gaining weight.

Growth failure

Growth failure means that a child is not growing as expected.

Because children are still growing and developing, monitoring height, weight and puberty is an important part of paediatric IBD care.

🎯 Treatment goals

Clinical remission

Clinical remission generally means that your child’s symptoms have improved or disappeared.

However, your child’s doctor may also want to confirm that inflammation is controlled through tests or other measures.

Biochemical remission

This generally refers to blood or stool markers showing that inflammation is reduced or controlled.

Your gastroenterologist will interpret these results alongside your child’s symptoms and other tests.

Endoscopic remission

This means that there are no visible signs of active inflammation during an endoscopic examination.

You may also hear doctors talk about mucosal healing.

Mucosal healing

The mucosa is the inner lining of the digestive tract.

Mucosal healing means that the lining has healed and there are no, or very few, visible signs of active inflammation during endoscopy.

👩‍⚕️ Your child’s healthcare team

Paediatric gastroenterologist

A paediatric gastroenterologist is a doctor who specialises in digestive conditions in children and teenagers.

They are often the specialist responsible for managing a child’s IBD treatment.

IBD nurse

An IBD nurse specialises in caring for people with inflammatory bowel disease.

They can often be an important point of contact for families between gastroenterology appointments.

IBD dietitian

An IBD dietitian has expertise in nutrition and can help families understand their child’s nutritional needs, growth and dietary concerns.

Multidisciplinary team

You may hear the term multidisciplinary team, or MDT.

This means a group of healthcare professionals who work together to care for your child.

The team may include doctors, nurses, dietitians, psychologists and other specialists.

🧠 A few other words you may hear

Gastroenterologist

A gastroenterologist is a doctor who specialises in the digestive system.

A paediatric gastroenterologist specialises in digestive conditions in children.

GI tract

GI stands for gastrointestinal.

The GI tract, or gastrointestinal tract, is the digestive system.

Digestive tract

Another term for the gastrointestinal tract.

It includes organs involved in moving and digesting food through the body.

Small bowel

The small bowel, or small intestine, is the part of the digestive tract between the stomach and large bowel.

It is where much of the digestion and absorption of nutrients takes place.

Large bowel

The large bowel, or colon, is the part of the digestive tract that absorbs water and forms stool.

Ulcerative colitis affects the large bowel.

Perianal disease

This refers to Crohn’s disease affecting the area around the anus.

It can include problems such as fissures, abscesses or fistulas.

Your child’s gastroenterologist may involve other specialists if perianal disease occurs.

Fistula

A fistula is an abnormal connection that develops between two parts of the body.

Fistulas can occur in some people with Crohn’s disease.

Abscess

An abscess is a collection of pus caused by infection.

Some children with Crohn’s disease can develop abscesses, including around the bowel or anus.

❤️ Don’t feel like you need to know all of this

There can be a lot of new terminology when your child is diagnosed with IBD.

You might hear a word at an appointment and think:

“I have absolutely no idea what that means.”

That’s okay.

Ask your child’s gastroenterologist to explain it.

Write unfamiliar words down and look them up using reliable sources. You can also ask your healthcare team which websites and resources they recommend for your child’s specific diagnosis.

Over time, words like calprotectin, remission, biologic and inflammation will become much more familiar.

You don’t need to learn the entire IBD dictionary at once.

One new word at a time is enough.

📝 Quick IBD glossary

IBD

Inflammatory bowel disease

Crohn’s disease

IBD that can affect anywhere along the digestive tract

Ulcerative colitis

IBD affecting the large intestine

Flare

A period of increased disease activity

Remission

When IBD is under control

Inflammation

The body’s inflammatory response

Calprotectin

A stool marker that can help measure intestinal inflammation

CRP

A blood marker that can indicate inflammation

Colonoscopy

A procedure used to examine the large intestine

Endoscopy

A procedure used to examine parts of the digestive tract

Biopsy

A small tissue sample examined under a microscope

Biologic

A medicine that targets specific parts of the immune or inflammatory response

EEN

Exclusive enteral nutrition

Paediatric gastroenterologist

A doctor specialising in digestive conditions in children

Mucosal healing

Healing of the inner lining of the digestive tract

You don’t have to know it all

There can be a lot of new words to learn when your child is diagnosed with IBD. It’s completely normal to feel overwhelmed by medical terms, test results and treatment language.

You don’t need to remember everything at once — and it’s always okay to ask your child’s IBD team to explain something again.

The more familiar these terms become, the easier it can be to understand what is happening with your child’s Crohn’s disease or ulcerative colitis and feel more confident at appointments.