Colonoscopy In Children

Colonoscopy In Children

A colonoscopy (lower endoscopy) is a procedure that looks inside the lower part of the digestive tract (bowel). Colonoscopies help doctors diagnose and monitor medical conditions. Find out more about what a colonoscopy involves.

Lower endoscopy: Guide for children

A short animation for children about what to expect before and during a lower endoscopy.
Please note - some content is specific to America and may not be relevant to New Zealand. Your hospital’s process may differ.
Video by Children's Hospital of Wisconsin. 


Key points about a colonoscopy in children

  • a colonoscopy is a procedure that looks inside the lower digestive tract (bowel)
  • your child will need to prepare for a colonoscopy so the doctor can see clearly
  • colonoscopies help doctors diagnose and manage medical conditions
  • your child will have an anaesthetic to put them to sleep during the procedure
  • tamariki (children) can usually go home on the same day as their procedure
  • if your child is unwell after their colonoscopy, contact the hospital or take them to see a doctor

What is a colonoscopy? 

A colonoscopy is a procedure that looks inside the lower part of the digestive tract - at the colon and rectum. 

Illustration showing lower digestive tract anatomy

A colonoscope is a thin, flexible tube with a camera and light on the end. The doctor puts the colonoscope into the bottom and slowly moves it along the colon. The doctor can look inside and take small tissue samples (biopsies) if needed.

The doctor might sometimes do a gastroscopy at the same time as a colonoscopy. A gastroscopy looks at the upper part of the digestive tract.

See the KidsHealth page on gastroscopy for more information

Why does my child need a colonoscopy?

Find a cause for symptoms

A colonoscopy helps doctors to diagnose medical conditions. The main reason a child may need a colonoscopy is to find a cause for: 

  • tummy pain
  • bleeding from the digestive tract
  • ongoing loose, watery poo (diarrhoea)
  • a change in bowel habit that continues for more than a few weeks (such as going often with more watery poo)

Monitor a medical condition

If your child has an ongoing medical condition such as inflammatory bowel disease, they may need regular colonoscopies. Colonoscopies help doctors monitor for any changes inside the bowel and help them see if certain treatments are working.   

If there is a bowel condition that runs in your whānau (family), your child may need a colonoscopy to check if they have it. 

See the KidsHealth page on inflammatory bowel disease for more information. 

Take biopsies

During the colonoscopy, the doctor can take tiny tissue samples from the lining of the bowel. These tissue samples are called biopsies. Biopsies are looked at under a microscope in the laboratory. The results of biopsies can help confirm whether or not your child has certain medical conditions. It can take up to a few weeks to get biopsy results.

Remove a polyp

A polyp is a small overgrowth of tissue, shaped a bit like a mushroom. Polyps grow from the lining of the bowel. The doctor can do a polypectomy if they find a polyp during a colonoscopy. A polypectomy is the removal of a polyp using special tools at the end of the colonoscope. 

Who will do my child’s colonoscopy?

It may be a gastroenterologist or a surgeon who will do your child’s colonoscopy.

A gastroenterologist is a doctor who specialises in the digestive system. A surgeon is a doctor who is trained to do different surgeries and procedures. 

How does my child prepare for a colonoscopy?

Your child’s bowel needs to be completely empty before the colonoscopy. This gives the doctor a clear view.

Preparation for a colonscopy begins at home and includes: 

  • avoiding certain medicines leading up to the procedure
  • taking medicine that clears out the bowel (called ‘bowel prep’)

What does my child need to avoid before a colonoscopy?

A week before the procedure

If your child is on any medicines that contains iron, the doctor may ask you to stop them a week before the colonoscopy. Your child can continue with most other medicines leading up to the colonoscopy. Talk to your child's doctor about this before the procedure.

The day before the procedure 

Your appointment letter will tell you what your child can have the day before their procedure. They must stop all milk and food at the time written in the appointment letter.

After stopping all food, your child can only have clear fluids. Clear fluids can be seen through easily.

Clear fluids and drinks that are OK before a colonoscopy include:

  • water
  • lemonade and lemonade ice blocks
  • cordial
  • clear sports drinks or oral rehydration drinks 
  • some types of jelly (not red or green jelly)

Milk and fresh fruit juice are not clear fluids.

What is involved in bowel prep before my child's colonoscopy?

Tamariki usually need to prepare for their colonoscopy at home before they go into hospital. Sometimes, tamariki may need to have their preparation in hospital. 

The gastroenterologist will give you specific advice to help prepare your child. Bowel prep is a drink that empties the bowel. It makes it easier for the doctor to see the inside more clearly. Tamariki must take the whole amount to make sure the bowel is empty.

Most tamariki will need to have bowel prep before their colonoscopy. They usually take this the evening before. Sometimes they may need to take it on the morning of the procedure. 

Tamariki using bowel prep at home will need to have extra clear drinks beforehand. This stops them from becoming dehydrated. The bowel prep will cause your child’s poo to become watery and loose. It may be best to avoid leaving the house during this time. Be prepared that they can have some leaking and accidents. 

What will happen on the day of my child’s colonoscopy?


Your child will not be able to eat for a time period before their colonoscopy. They can have clear fluids up to a certain time. Check their appointment letter for instructions on when they need to stop eating and drinking. 

General anaesthetic 

Your child will have a light anaesthetic to put them to sleep during the procedure. 

See the KidsHealth page on anaesthetic for more information.

Procedure timing 

A colonoscopy usually takes around 30 minutes but may take longer, depending on the doctor's findings. 

If your child is having a gastroscopy as well as a colonoscopy, that procedure will take longer. See the KidsHealth page on gastroscopy for more information


After the colonoscopy, your child will go to a recovery area. You can join them there.

Can my child go home after their colonoscopy? 

A colonoscopy is a day procedure. Tamariki can usually go home the same day. 

What can I expect after my child's colonoscopy?


After your child has gone home, they should rest for the remainder of the day. They should be able to return to their usual activities, like school, the following day. 


Once you are home, your child can eat a light diet when they feel like eating. 

Light foods include things like:

  • soup
  • pasta
  • sandwiches
  • jelly 

The day after their procedure, they can return to eating normally if they feel ready.

Pēpi (babies) can start breastfeeding or drinking formula or water as soon as they wake up from the procedure.


Because of the anaesthetic, rangatahi (young people) should not operate machinery, drive or make important decisions for the rest of the day after their procedure. 


A doctor or nurse will speak to you after the procedure to let you know how it went. If your child had biopsies taken, it can take a few weeks to get the results. The doctor or nurse will make a plan with you on how to follow up on these results. They may ask you to contact your child’s GP clinic after a few weeks if you haven't had any results back. 

Are there any side effects from having a colonoscopy? 

Tamariki may have side effects following a colonoscopy. If you have any concerns, you should contact the hospital or take them to see a doctor. 

Nausea and vomiting

If your child feels sick after their procedure, stop them from eating and drinking for 30 minutes. You can then offer them clear fluids. If they feel ready, you can slowly increase what they eat and drink. 

Tummy pain and bloating

Mild tummy pain can occur after a colonoscopy. Make sure your child rests and offer them sips of clear fluid until it settles. It is normal for tamariki to fart more after a colonoscopy. 


Sometimes, there can be a small amount of blood in the poo after a colonoscopy. This can happen if biopsies are taken during the procedure. 

When should I take my child to see a doctor?

Call the hospital or take your child to see a doctor if they have any of the following after their colonoscopy:

  • more than 3 vomits 
  • if you see more than half a teaspoon of bright red blood in their poo or vomit
  • severe tummy pain
  • severe bloating 
  • fever (temperature over 38 degrees Celsius) 
  • they appear unwell or are difficult to settle

If you have any concerns, you should contact the hospital or take them to see a doctor. 


Illustration by Dr Greta File. Property of KidsHealth. 

This page last reviewed 16 January 2024.

Call Healthline on 0800 611 116 any time of the day or night for free health advice when you need it