Introduction
Endoscopy is a “camera test” used to diagnose and often treat conditions affecting the digestive system. It is performed using a thin flexible telescope with a camera, typically under sedation or anaesthetic, and does not involve surgical cuts.
The two most common procedures are:
- Gastroscopy (Upper Endoscopy / OGD): examines the oesophagus, stomach, and duodenum (first part of the small bowel).
- Colonoscopy (Lower Endoscopy): examines the rectum and colon and can treat issues such as polyp removal.
Why it matters: in common situations such as reflux , iron deficiency anaemia, unexplained weight loss, or a positive bowel screening test—endoscopy can identify the cause early and, in many cases, manage it during the same procedure.
Gastroscopy (Upper Endoscopy / OGD)
What gastroscopy assesses
Gastroscopy allows close inspection of the lining of the:
- Oesophagus
- Stomach
- Duodenum
It also allows biopsies (small tissue samples) to help diagnose conditions such as:
- inflammation (gastritis/oesophagitis)
- infection (e.g., H. pylori)
- Barrett’s oesophagus
- coeliac disease
- ulcers or other abnormalities
When gastroscopy is commonly recommended ?
A gastroscopy may be advised for:
- Persistent reflux/heartburn, especially with “alarm” features (e.g., difficulty swallowing, bleeding, anaemia, or weight loss)
- Upper abdominal pain, indigestion, nausea/vomiting
- Swallowing symptoms (food sticking, pain with swallowing)
- Upper GI bleeding (vomiting blood, black stools)
- Unexplained iron deficiency anaemia (depending on the overall clinical picture)
Preparation (typical)
Your clinic will provide exact instructions, but commonly:
- Fasting is required prior to the procedure (our team will advise you in regards to the duration)
- A medication review is essential (especially diabetes medications and blood thinners)
Do not stop medications unless specifically instructed.
- Plan for the day: you should not drive, operate machinery, drink alcohol, or make important decisions after sedation
What happens on the day (step-by-step)
- Consent and safety checks
- Sedation/anaesthetic as appropriate
- The scope is passed through the mouth for careful inspection; biopsies may be taken if required
- Recovery monitoring until you are safe for discharge
Colonoscopy (Lower Endoscopy)
What colonoscopy assesses and can treat ?
Colonoscopy evaluates the:
- Rectum
- Colon (large bowel)
It is a key test for:
- follow-up after positive bowel screening tests
- investigation of polyps
- rectal bleeding (PR bleeding)
- change in bowel habit
- symptoms suggesting inflammation or other bowel disease
Importantly, colonoscopy can also treat certain conditions during the same procedure, most commonly by removing polyps (polypectomy) and taking targeted biopsies.
Bowel screening in Australia (FIT / iFOBT)
Australia’s National Bowel Cancer Screening Program offers eligible people aged 45–74 a free home stool test (FIT/iFOBT) every two years.
If FIT/iFOBT is positive, a colonoscopy is commonly recommended to identify the cause, which may include:
- polyps
- bowel cancer
- inflammation
- haemorrhoids and other benign sources of bleeding
Rectal bleeding (PR bleeding)
Whether colonoscopy is recommended depends on:
- age
- bleeding pattern/volume
- associated symptoms (e.g., bowel habit change)
- anaemia
- family history and other risk factors
Colonoscopy helps exclude serious pathology and may treat certain causes of bleeding.
Bowel preparation (critical for accuracy)
A well-prepared colon is essential. Good bowel preparation:
- improves detection of polyps/lesions
- reduces the chance of an incomplete procedure
- lowers the likelihood of needing an early repeat colonoscopy
Quality standards commonly emphasise split-dose bowel preparation (taking part of the prep the evening before and the remainder on the day) because it is associated with better visibility and improved detection (Our team will send you a detailed instructions for your bowel preparations- please follow our instructions for the best outcome)
What happens on the day (step-by-step)
- Consent and pre-assessment (prep quality, medications, and medical history)
- Sedation/anaesthetic
- Examination of the colon
- Treatment if required: biopsies, polyp removal (polypectomy)
- Recovery and discharge instructions
Complications & Risks
This section includes both:
- clinical situations where endoscopy may be urgent, and
- the risks related to the procedure itself.
A) Situations where endoscopy is often urgent
- significant gastrointestinal bleeding
- severe anaemia where GI blood loss is suspected
- concerning symptoms such as progressive swallowing difficulty or unexplained weight loss with GI symptoms
B) Procedure risks (gastroscopy and colonoscopy)
Serious complications are uncommon, but it is important to understand the key risks:
- Sedation/anaesthetic risks: breathing or cardiovascular complications, particularly in patients with significant underlying medical conditions
- Bleeding: more likely if biopsies are taken or polyps are removed
- Infection: rare, with risk minimised through strict cleaning and reprocessing standards
- Perforation (tear/hole): rare but serious; risk is higher with more complex therapy (e.g., larger polypectomy)
- Incomplete procedure / missed lesions: can occur, especially with poor bowel preparation, anatomical difficulty, or patient safety limitations
Related Investigations & Pre-Procedure Assessment
Endoscopy is often part of a broader diagnostic pathway. Prior to endoscopy, your clinician may arrange:
- Blood tests (e.g., anaemia assessment, inflammation markers, liver function)
- Stool tests, including FIT/iFOBT where appropriate
- Imaging (e.g., ultrasound or CT) depending on symptoms
Pre-procedure assessment focuses on:
- existing medical conditions (heart/lung disease, sleep apnoea, kidney disease)
- medications: especially anticoagulants/antiplatelets and diabetes therapies
- prior sedation reactions and allergies
- tailoring a bowel preparation plan to the individual patient
How Endoscopy Can Help (Diagnosis & Treatment)
Endoscopy is not only diagnostic many conditions can be treated during the procedure.
During gastroscopy, this may include:
- biopsies to clarify diagnosis
- management of certain bleeding lesions (case-dependent)
- surveillance planning for Barrett’s oesophagus (with intervals determined by risk and guideline recommendations)
During colonoscopy, this may include:
- polypectomy to reduce bowel cancer risk
- biopsies to assess inflammation/IBD (colitis)
- treatment of selected bleeding sources (case-dependent)
Haemorrhoids and PR bleeding: Rubber Band Ligation (RBL)
When painless bright red rectal bleeding is due to internal haemorrhoids, management often follows a stepwise approach:
- dietary fibre and bowel habit optimisation
- office-based procedures if symptoms persist
Rubber band ligation (RBL) is widely used and can be very effective for suitable haemorrhoid grades, particularly after conservative measures have been tried.
Important note: RBL only for internal haemorrhoids , external haemorrhoids can not be treated with RBL and if require treatment require surgery under general anaesthesia
Post-Procedure Care & When to Seek Help
After sedation
It is normal to feel drowsy. For the remainder of the day:
- do not drive or operate machinery
- avoid alcohol
- do not make important decisions
- follow discharge instructions carefully
Seek urgent medical attention if you develop:
- severe or worsening abdominal or chest pain
- fever
- significant bleeding, dizziness, or fainting
- persistent vomiting
Why a repeat procedure may be needed
Repeat endoscopy/colonoscopy may be required if:
- bowel preparation was inadequate
- the scope could not safely reach the endpoint
- visibility was limited and important pathology was suspected
Otherwise, repeat timing should follow guideline-based surveillance intervals.
Guidelines & Evidence (Australia + International)
Your care should align with established standards and surveillance recommendations, including:
- Australian bowel cancer screening guidance (FIT/iFOBT program)
- Australian colonoscopy quality and clinical care standards (consent, bowel prep quality, appropriate indications, repeat procedures)
- GESA patient information resources for procedure expectations
- Endoscopy infection prevention and reprocessing standards
- International guidance commonly referenced in practice (e.g., post-polypectomy surveillance intervals, Barrett’s surveillance, haemorrhoid management recommendations)
Summary
Gastroscopy and colonoscopy are commonly performed endoscopic procedures used to investigate and manage digestive symptoms.
- Gastroscopy examines the oesophagus, stomach, and duodenum for reflux, ulcers, swallowing problems, upper GI bleeding, and Barrett’s oesophagus, often with biopsies.
- Colonoscopy examines the colon and rectum and is commonly recommended after a positive FIT/iFOBT or for rectal bleeding and bowel habit changes. It can also treat problems at the same time, particularly through polyp removal and biopsies.
- Endoscopy is generally safe, but key risks include sedation complications, bleeding, infection, perforation, incomplete procedures, and missed lesions, especially when bowel preparation is poor.
