Colonoscopy
Investigation of bowel symptoms and bowel cancer surveillance
We provide comprehensive and personalised colonoscopy services.
Colonoscopy is used to investigate bowel symptoms and to diagnose conditions including colorectal cancer, colonic polyps, diverticular disease and inflammatory bowel disease — Crohn's disease and ulcerative colitis.
This procedure allows us to directly examine the mucosa (lining) of the rectum, colon and terminal ileum, the final part of the small intestine. Colonoscopy requires the bowel to be cleared to give us the best possible views, and is performed under sedation.
During a colonoscopy we can diagnose abnormalities by direct inspection and confirm findings by biopsy. We can also treat some abnormalities, such as removing polyps — which reduces the subsequent risk of bowel cancer.
Colonoscopy is performed at Southern Endoscopy Centre, Christchurch.
Diagnostic and therapeutic colonoscopy
Bowel screening looks for early signs of bowel cancer in people who have no symptoms. New Zealand has one of the highest rates of bowel cancer in the world, and screening finds it at a stage when it can often be successfully treated.
The National Bowel Screening Programme is free and is run by Health New Zealand, not by GES. If you are eligible, a test kit is posted to you every two years. In Canterbury the programme currently starts at age 58 and runs to 74; from 30 September 2026 the starting age lowers to 56. If your test finds blood, you will be offered a colonoscopy to find out what is causing it.
If you have bowel symptoms that concern you, see your GP without delay — whatever your age, and whether or not you have had a recent screening test. If you have a family history of bowel cancer, you may need regular colonoscopy rather than screening.
At Stewart Street Specialists, 7 members of our team are accredited bowl cancer screeners. Our specialists are closely involved in bowel screening in New Zealand: Dr Teresa Chalmers-Watson has been Clinical Lead for the National Bowel Screening Programme in Waitaha, Canterbury since 2020, and Dr Jan Kubovy is a programme endoscopist.
Bowel screening
What is a colonoscopy?
What is a colonoscopy?
Colonoscopy enables your doctor to carefully examine the lining of the colon, also called the large bowel. It is performed using a colonoscope, a flexible tube about the thickness of a finger, which has a wide-angled camera in the tip. The images are transmitted to a monitor that your specialist watches throughout.
What preparation is required?
What preparation is required?
It is essential that the bowel is completely clean, so that the procedure is safe, accurate and complete. In general this means a low fibre, low residue diet for three days beforehand and a bowel preparation solution the day before. The exact details of when and what to take will be sent to you with your appointment letter.
Tell us as soon as possible before your examination if you take insulin, aspirin or blood thinners such as warfarin, clopidogrel or dabigatran. If you take iron tablets, stop one week beforehand. Please also tell us about any allergies.
What can I expect during the procedure?
What can I expect during the procedure?
A colonoscopy is performed in a fully equipped theatre and is generally well tolerated. Your doctor will give you an intravenous sedative to help you relax, and you will be monitored throughout. The procedure usually takes around 30 minutes, though longer if polyps are removed — allow a total of two hours for the procedure and recovery.
What are polyps, and why are they removed?
What are polyps, and why are they removed?
Polyps are abnormal growths in the colon lining. They are usually benign, but if left they may become cancerous over time. Because bowel cancer begins in polyps, removing them is an important means of preventing it. They are removed painlessly during the colonoscopy and sent to the laboratory for analysis.
What happens afterwards, and what are the risks?
What happens afterwards, and what are the risks?
You will be monitored in recovery until the sedative wears off, then your doctor will explain the results — though biopsy results take up to five days. Someone must drive you home and stay with you, and you should not drive, operate machinery, make important decisions or drink alcohol for 24 hours.
Colonoscopy is generally safe when performed by trained, experienced specialists. Significant complications occur in up to 1 in 1,000 patients, the most serious being perforation of the bowel wall and bleeding. Contact your specialist if you notice severe abdominal pain, fever and chills, or rectal bleeding of more than half a cup — bleeding can occur several days afterwards.
Have more questions?
If you still have any questions about the procedure, the reasons for doing it, any alternative tests, the costs, or insurance coverage do not hesitate to contact us.
get in touch
Ask your GP to refer you to one of our specialists, or contact us to discuss your options and arrange a consultation.
