If your GP has referred you for a colonoscopy, it is normal to have questions about what the procedure involves, why it has been recommended, how to prepare and what happens afterwards. Many people feel nervous before a colonoscopy, especially if it is their first time. Understanding the process can make the experience feel much more manageable.
A colonoscopy is a procedure used to examine the large bowel, also called the colon, and the rectum. It uses a thin, flexible tube with a small camera and light at the end. This allows a specialist to carefully view the bowel lining and look for polyps, inflammation, bleeding, bowel cancer or other abnormalities.
Direct Endoscopy provides colonoscopy in Melbourne across multiple locations, including Frankston, Hampton, Bayswater, Narre Warren and Rosebud. Colonoscopy may be recommended for symptoms such as rectal bleeding, persistent changes in bowel habits, unexplained iron deficiency, abdominal pain, a positive bowel screening test or a history of bowel polyps.
This guide explains what a colonoscopy is, why your doctor may recommend it, how to prepare, what happens during the procedure and what to expect after your appointment.
Article index
- What is a colonoscopy?
- Why might your doctor recommend a colonoscopy?
- Symptoms that may be investigated with colonoscopy
- Colonoscopy after a positive bowel screening test
- What can a colonoscopy detect?
- Bowel polyps and why they matter
- Colonoscopy and bowel cancer detection
- How to prepare for a colonoscopy
- Why bowel preparation is important
- Medications before colonoscopy
- What happens during the procedure?
- Sedation and comfort during colonoscopy
- Can biopsies or polyps be removed during colonoscopy?
- What happens after colonoscopy?
- When will you get your results?
- Colonoscopy vs gastroscopy: what is the difference?
- Colonoscopy vs capsule endoscopy
- Is colonoscopy safe?
- When to seek medical advice after colonoscopy
- How Direct Endoscopy can help
- Final thoughts
What is a colonoscopy?
A colonoscopy is a medical procedure used to examine the inside of the large bowel and rectum. The procedure is performed using a colonoscope, which is a long, thin and flexible tube with a camera and light at the tip.
The colonoscope is gently inserted through the rectum and guided around the large bowel. The camera sends images to a screen, allowing the specialist to carefully inspect the lining of the bowel. The aim is to identify any areas of concern, such as polyps, inflammation, bleeding, narrowing, abnormal tissue or signs of bowel cancer.
Healthdirect’s colonoscopy guide explains that colonoscopy allows a doctor to view the inside of the large bowel using a camera. Better Health Channel also describes colonoscopy as a procedure used to examine the large bowel using a flexible tube with a tiny camera and light.
A colonoscopy is usually performed as a day procedure. Most patients receive sedation or a light anaesthetic to keep them comfortable during the procedure.
Why might your doctor recommend a colonoscopy?
Your doctor may recommend a colonoscopy when symptoms, screening results, blood tests or your medical history suggest that the large bowel needs to be examined more closely.
Some bowel symptoms can be caused by minor or short-term problems. However, symptoms that are persistent, unexplained, worsening or associated with other risk factors may need investigation. Colonoscopy allows the specialist to look directly at the bowel lining rather than relying on symptoms alone.
A colonoscopy may also be recommended after a positive bowel screening test. The home bowel screening test can detect hidden blood in the stool, but it cannot show where the blood came from. Colonoscopy helps identify the cause of bleeding.
If your GP has referred you for a colonoscopy, it is usually because they want to investigate your symptoms, screening result, family history, previous polyps or another bowel health concern.
Symptoms that may be investigated with colonoscopy
Colonoscopy may be recommended for a range of bowel symptoms. These symptoms do not always mean there is a serious condition, but they should be assessed if they are persistent, unexplained or concerning.
Symptoms that may lead to colonoscopy include:
- Rectal bleeding
- Blood in the stool
- A persistent change in bowel habits
- Ongoing diarrhoea or constipation
- A feeling that the bowel does not empty properly
- Unexplained abdominal pain or cramping
- Unexplained iron deficiency anaemia
- Unexplained weight loss
- Narrower stools or a noticeable change in stool appearance
- A positive bowel screening test result
These symptoms can have many causes, including haemorrhoids, irritable bowel syndrome, infections, inflammatory bowel disease, diverticular disease, medication effects or bowel cancer. Colonoscopy helps your doctor investigate what may be causing the symptoms.
Colonoscopy after a positive bowel screening test
A colonoscopy is commonly recommended after a positive bowel screening test result. The bowel screening test, also known as a faecal occult blood test or immunochemical faecal occult blood test, checks for tiny traces of blood in the stool. This blood may not be visible to the naked eye.
A positive bowel screening test does not mean you definitely have bowel cancer. It means blood was found in the sample and the cause needs to be investigated. Possible causes include polyps, haemorrhoids, inflammation, diverticular disease or bowel cancer.
The Australian Government’s guidance on bowel screening test results advises people with a positive result to see their GP to find out what is causing the bleeding. In many cases, the GP will refer the patient for colonoscopy.
If you have received a positive bowel screening result, do not ignore it and do not rely on simply repeating the test for reassurance. Speak with your GP and follow their advice about further investigation.
What can a colonoscopy detect?
A colonoscopy can help detect a wide range of bowel conditions. Some findings may be minor, while others may need treatment, monitoring or specialist follow-up.
Colonoscopy can help detect:
- Bowel polyps
- Bowel cancer
- Inflammation in the large bowel
- Ulcerative colitis
- Crohn’s disease affecting the colon
- Diverticular disease
- Possible causes of rectal bleeding
- Possible causes of unexplained iron deficiency anaemia
- Abnormal tissue or narrowing in the bowel
In some cases, the colonoscopy may look normal. A normal result can still be useful because it helps rule out certain serious causes of symptoms and may guide your doctor towards other explanations.
If abnormalities are seen, biopsies may be taken or polyps may be removed. These samples are usually sent to a laboratory for testing.
Bowel polyps and why they matter
Polyps are small growths that can develop on the lining of the bowel. Many polyps are benign, meaning they are not cancer. However, some types of polyps can develop into bowel cancer over time if they are not detected and removed.
One of the important benefits of colonoscopy is that polyps can often be removed during the procedure. This is called polypectomy. Removing certain types of polyps may reduce the risk of those polyps developing into bowel cancer in the future.
Bowel Cancer Australia’s information on colonoscopy explains that colonoscopy allows the colonoscopist to examine the bowel lining and remove suspicious growths such as polyps.
If a polyp is removed, it will usually be sent to a laboratory for analysis. The results help determine whether further follow-up is needed and when your next colonoscopy should occur.
Colonoscopy and bowel cancer detection
Colonoscopy is an important procedure for investigating possible bowel cancer. It may be recommended because of symptoms, a positive bowel screening result, unexplained iron deficiency anaemia, abnormal imaging, previous polyps or family history.
Bowel cancer can sometimes develop without obvious early symptoms. This is why screening and timely follow-up are important. If bowel cancer is found early, treatment is more likely to be successful.
During colonoscopy, the specialist looks for changes in the bowel lining. If an abnormal area is seen, a biopsy can be taken and sent to a laboratory. If bowel cancer is diagnosed, your doctor will arrange appropriate referral and further tests.
A colonoscopy does not mean cancer is expected. Many colonoscopies find non-cancerous conditions or normal results. However, when cancer or pre-cancerous polyps are present, colonoscopy can play a key role in diagnosis and management.
How to prepare for a colonoscopy
Preparation is one of the most important parts of colonoscopy. The bowel needs to be as clean as possible so the specialist can clearly see the bowel lining. If the bowel is not properly prepared, small polyps or abnormalities may be missed, or the procedure may need to be repeated.
Preparation usually involves changing your diet for a short period before the procedure and taking a bowel preparation solution as instructed. This solution causes the bowel to empty. Although the preparation can be inconvenient, it is essential for a safe and effective examination.
Direct Endoscopy provides detailed colonoscopy preparation instructions for patients. These instructions should be followed carefully unless your doctor or the clinic gives you different advice.
If you have diabetes, kidney disease, heart disease, are pregnant, take blood thinners or take regular medication, tell your doctor and the clinic before the procedure. You may need individual preparation advice.
Why bowel preparation is important
Bowel preparation is important because stool can hide parts of the bowel lining. The cleaner the bowel, the easier it is for the specialist to see polyps, inflammation, bleeding or abnormal tissue.
Direct Endoscopy’s colonoscopy patient preparation information states that proper patient preparation is very important for the procedure to be successful and safe, and that the bowel must be as clear as possible or the examination may need to be postponed and repeated.
Good preparation also helps reduce the chance of needing another colonoscopy sooner than expected due to poor visibility. If you are unsure about any part of the preparation instructions, contact the clinic before the procedure.
It is important to stay near a toilet after taking the bowel preparation, as it will cause frequent bowel motions. You should also follow the instructions about clear fluids, timing and when to stop drinking before the procedure.
Medications before colonoscopy
Before your colonoscopy, you will be asked about your medications, allergies and medical history. This is important for both the bowel preparation and the procedure itself.
Some medications may need special instructions. These can include blood thinners, diabetes medications, iron tablets, anti-inflammatory medications and medications that affect kidney function or fluid balance. Do not stop prescribed medication unless your doctor or the clinic tells you to do so.
If you take blood thinners, tell your doctor and the clinic well before your procedure. The advice may depend on why you take the medication, your risk of clotting, your risk of bleeding and whether polyp removal is expected.
If you have diabetes, fasting and bowel preparation can affect blood sugar levels. You may need specific instructions about insulin, tablets, food intake and fluid intake before the procedure.
What happens during the procedure?
On the day of your colonoscopy, you will be admitted and checked by the clinical team. They may confirm your details, medical history, allergies, medications, preparation quality and when you last ate or drank.
Most patients receive sedation or a light anaesthetic to help them stay comfortable. The colonoscope is then gently inserted through the rectum and guided around the large bowel. The specialist examines the bowel lining on a monitor.
If polyps are found, they may be removed during the procedure. If an area needs further assessment, a biopsy may be taken. The specialist may also take photographs of areas of interest as part of the medical record.
The procedure itself usually does not take very long, but you should allow extra time for admission, sedation, recovery and discharge.
Sedation and comfort during colonoscopy
Many patients worry that colonoscopy will be painful. In most cases, sedation or a light anaesthetic is used to minimise discomfort during the procedure.
Healthdirect notes that sedation or a light anaesthetic is used during colonoscopy to minimise pain and discomfort. The Australian and New Zealand College of Anaesthetists also explains that endoscopy procedures such as gastroscopy and colonoscopy are frequently performed as day-stay procedures and may involve sedation or anaesthesia.
Your oxygen level, heart rate and blood pressure may be monitored during the procedure. The type and depth of sedation depend on the facility, anaesthetist, procedure and your medical history.
If you are anxious about the procedure, tell the clinical team. They can explain what will happen and how your comfort and safety will be managed.
Can biopsies or polyps be removed during colonoscopy?
Yes. One of the main advantages of colonoscopy is that biopsies can be taken and polyps can often be removed during the procedure.
A biopsy is a small tissue sample taken from the bowel lining and sent to a laboratory for analysis. Biopsies may be taken if the specialist sees inflammation, abnormal tissue or an area that needs closer examination. Biopsies may also be taken to help diagnose inflammatory bowel disease or other conditions.
Polyp removal may be performed if polyps are found and it is safe to remove them during the procedure. The removed polyp is then sent for pathology testing.
If a large or complex polyp is found, it may not always be removed immediately. Your doctor may recommend referral for a more specialised procedure or follow-up plan depending on the size, location and appearance of the polyp.
What happens after colonoscopy?
After the colonoscopy, you will be moved to a recovery area while the sedation wears off. You may feel drowsy for a while. Some patients feel bloated or pass wind after the procedure because air or carbon dioxide may be used to help the specialist see the bowel lining clearly.
Because sedation is used, you will need someone to take you home. You should not drive, operate machinery, drink alcohol or make important decisions for the rest of the day. Bowel Cancer Australia’s colonoscopy preparation information notes that patients who receive sedation cannot drive themselves home after colonoscopy.
Your doctor or the clinical team will explain the initial findings. If biopsies or polyps were taken, final results may take several days because they need to be examined in a laboratory.
Before leaving, make sure you understand your discharge instructions, when to restart medications, when to eat normally and when to seek medical advice.
When will you get your results?
Some colonoscopy findings can be explained shortly after the procedure. For example, your doctor may be able to tell you whether the bowel looked normal, whether inflammation was seen or whether polyps were removed.
If biopsies or polyps were sent to pathology, the final results may not be available immediately. Your doctor will explain how and when you will receive those results.
Your follow-up plan depends on what is found. If the colonoscopy is normal, your doctor may recommend routine follow-up or further investigation depending on your symptoms. If polyps are found, your doctor will advise when your next colonoscopy should occur. If inflammation or another condition is found, treatment or specialist follow-up may be recommended.
Do not assume that no news means no issue. If you have not received results within the timeframe advised, follow up with your doctor or clinic.
Colonoscopy vs gastroscopy: what is the difference?
Colonoscopy and gastroscopy are both endoscopy procedures, but they examine different parts of the digestive system.
A colonoscopy examines the large bowel and rectum. It is commonly used to investigate lower bowel symptoms such as rectal bleeding, changes in bowel habits, unexplained iron deficiency, abdominal pain or a positive bowel screening test.
A gastroscopy examines the upper digestive tract, including the oesophagus, stomach and duodenum. It may be used to investigate reflux, heartburn, difficulty swallowing, upper abdominal pain, nausea, vomiting, anaemia or suspected ulcers.
Direct Endoscopy provides both colonoscopy services in Melbourne and gastroscopy services in Melbourne. In some cases, both procedures may be performed during the same appointment if your doctor needs to investigate both the upper and lower digestive tract.
Colonoscopy vs capsule endoscopy
Colonoscopy and capsule endoscopy are also different procedures. Colonoscopy examines the large bowel and rectum using a flexible camera inserted through the rectum. It allows the specialist to take biopsies and remove polyps if needed.
Capsule endoscopy involves swallowing a small camera capsule that travels naturally through the digestive tract and takes images, especially of the small bowel. It is often used when the small bowel needs to be assessed, particularly if gastroscopy and colonoscopy do not explain symptoms or bleeding.
Capsule endoscopy does not usually allow biopsies or polyp removal. It is mainly a diagnostic imaging test. Colonoscopy is both diagnostic and, in some cases, therapeutic because polyps can often be removed during the procedure.
Direct Endoscopy provides capsule endoscopy for suitable patients who need small bowel investigation. Your GP or specialist can advise whether colonoscopy, gastroscopy, capsule endoscopy or another test is most appropriate for your symptoms.
Is colonoscopy safe?
Colonoscopy is commonly performed and is generally considered safe. However, like all medical procedures, it has potential risks. These can include reactions to sedation, bleeding, especially after polyp removal, infection or, rarely, a tear or perforation in the bowel wall.
Healthdirect notes that complications such as bleeding during or after colonoscopy are rare. The level of risk can vary depending on your age, medical history, medications, bowel preparation quality and whether biopsies or polyp removal are performed.
Your doctor and the clinical team will consider your individual situation before the procedure. Make sure you tell them about allergies, previous anaesthetic problems, heart or lung disease, diabetes, kidney disease, bleeding problems, pregnancy or blood-thinning medication.
For many patients, the benefits of investigating important bowel symptoms or following up a positive bowel screening test outweigh the risks. Your GP or specialist can discuss your personal risk and explain why the procedure has been recommended.
When to seek medical advice after colonoscopy
Most people recover well after colonoscopy. Mild bloating, wind or drowsiness after sedation can occur and usually settles. However, some symptoms need prompt medical advice.
Seek medical advice promptly if you experience:
- Severe or worsening abdominal pain
- Persistent vomiting
- Fever or chills
- Heavy rectal bleeding
- Black or bloody stools that are not expected
- Dizziness, fainting or severe weakness
- Chest pain or shortness of breath
- Any symptom that feels unusual or concerning after the procedure
If symptoms are severe or urgent, seek emergency medical care. If you are unsure whether a symptom is expected, contact the clinic or your doctor for advice.
How Direct Endoscopy can help
Direct Endoscopy provides specialist gastroenterology and endoscopy services across multiple Melbourne locations, including Frankston, Hampton, Bayswater, Narre Warren and Rosebud. Patients can view all hospital locations on the locations page.
For patients with rectal bleeding, bowel habit changes, positive bowel screening results, previous polyps, unexplained iron deficiency or other bowel concerns, Direct Endoscopy provides colonoscopy in Melbourne in accredited hospital settings.
Direct Endoscopy can assist with booking, preparation instructions, the procedure and follow-up guidance. Patients preparing for their procedure can read the colonoscopy preparation instructions before their appointment.
Patients can also visit the Direct Endoscopy book online page for more information about appointment options.
Final thoughts
A colonoscopy is a procedure used to examine the large bowel and rectum. It can help investigate symptoms such as rectal bleeding, changes in bowel habits, unexplained iron deficiency, abdominal pain and positive bowel screening results.
It can also detect and remove bowel polyps, identify inflammation, take biopsies and help diagnose bowel conditions. While preparation can be inconvenient, good bowel preparation is essential for a clear and accurate examination.
If your GP has recommended a colonoscopy, it is because they want to understand what is happening inside your bowel and guide the right next steps. If you have been referred for colonoscopy, Direct Endoscopy can help you understand the process, prepare correctly and receive specialist endoscopy care.