Quick answer: The colonoscopy itself usually takes 15–30 minutes. However, including preparation, any anaesthesia required and the post-procedure observation period, the entire process can take up to 2–3 hours. If polyps are removed, the procedure may take even longer.
If you’re wondering how long a colonoscopy takes and what to expect at the clinic, you’ve come to the right place. A colonoscopy is one of the most effective methods for screening for bowel cancer and investigating gastrointestinal symptoms – yet many people put it off due to fear or uncertainty. This article explains exactly how long a colonoscopy takes, how it is carried out step by step, and what to expect before, during and after the procedure.
The better you understand the process, the better prepared you’ll be for the examination.
How long does a colonoscopy actually take?
Many people worry that the examination will be long and uncomfortable. The reality, however, is that the procedure itself is surprisingly short.
The actual duration of the examination is 15–30 minutes. This is the stage at which the doctor uses a thin, flexible instrument – an endoscope – to examine the entire large intestine, from the rectum right through to the final section of the small intestine. During the examination, the doctor carefully examines the intestinal mucosa: whilst withdrawing the instrument, they spend at least 6–10 minutes carefully examining the mucosa. This is known as the withdrawal time, and it is one of the most important quality indicators of a well-performed colonoscopy.
However, when the entire process is taken into account, the time spent at the surgery is considerably longer than this:
- Registration and preparation: 15–30 minutes
- The investigation itself: 15–30 minutes
- Post-anaesthesia monitoring: 30–60 minutes (for examinations under anaesthesia)
All in all, therefore 2–3 hours a realistic expectation regarding the time spent at the surgery.
What factors influence the duration of a colonoscopy?
Not all examinations take the same amount of time. A number of factors can influence how long your colonoscopy will take.
Intestinal preparation
A thoroughly cleansed colon is a prerequisite for the examination. If the bowel has not been adequately prepared, the doctor will not be able to see the mucosa clearly, which may prolong the examination – or even make it necessary to repeat the procedure. Bowel cleanliness is assessed using the BBPS (Boston Bowel Preparation Scale) scoring system: a total score of over 6 points is required for an optimal result, with a minimum of 2 points for each section of the bowel.
Anatomical characteristics
In some people, the natural bends in the large bowel make it difficult for the endoscope to advance. Adhesions resulting from previous abdominal surgery can also slow down the examination. Experienced gastroenterologists successfully reach the caecum in 90–98% of cases, but certain anatomical difficulties may increase the time required.
Therapeutic interventions during the study
If the doctor detects a polyp or any other abnormality, the examination may immediately turn into a therapeutic procedure. If a polyp is removed (polypectomy), a tissue sample is taken (biopsy) or bleeding is stopped, the duration of the procedure may increase significantly. The size and number of polyps determine the method of removal:
- Small polyps (≤ 9 mm): Cold-loop polypectomy: a quick and safe procedure
- Medium-sized polyps (10–19 mm): Removal using electrical current, with the use of submucosal injection
- Large polyps (≥ 20 mm): Specialised techniques (EMR, ESD) are required, which significantly extend the examination time
A step-by-step guide to a colonoscopy
Knowing exactly what is going to happen goes a long way towards reducing any anxiety about the examination. Here is the full process:
Step 1: Preparing the lining – the task to do at home
The success of the examination depends largely on the preparation. On the day before the examination, you will need to take a special bowel-cleansing preparation containing a laxative – usually a polyethylene glycol-based solution. At the same time, you must follow dietary guidelines (usually a low-residue diet, followed by a liquid-only diet).
It is important to be aware that taking iron supplements at least 5 days before the examination These should be suspended, as they make it difficult to examine the intestinal mucosa. If you are taking anticoagulant medication, you must inform your doctor, as in some cases it may be necessary to temporarily stop taking the medication.
Step 2: Arrival and registration
Once you arrive at the clinic, you will first complete the administrative formalities and undergo the necessary preparations for the examination. If the examination is to be carried out under anaesthesia, the anaesthetist will also examine you and explain the procedure to you.
Step 3: The examination
The examination is carried out whilst the patient is lying on their side. The doctor inserts the flexible endoscope through the rectum and slowly advances it through the entire length of the large intestine. As the instrument is withdrawn, the doctor examines the intestinal mucosa in detail. If a polyp or suspicious area is found, a sample is taken immediately or the polyp is removed.
Step 4: Awakening and observation
Following a colonoscopy under general anaesthesia, the patient is taken to a recovery room, where they are monitored until the effects of the anaesthetic have completely worn off. This usually takes 30–60 minutes. It is important that, following a procedure under general anaesthesia, do not drive, and leaves the surgery with the help of an accompanying person.
Anaesthesia during a colonoscopy: why is it preferable?
A colonoscopy can be performed whilst the patient is awake, under sedation (conscious sedation) or under general anaesthesia. During conscious sedation, the patient is semi-awake, which some patients may find uncomfortable – particularly if the doctor also needs to carry out a therapeutic procedure.
At Endomedix, for professional reasons, only We use anaesthesia, not sedation. Deep anaesthesia ensures complete pain relief; the patient lies motionless, which allows for a more thorough examination of the mucous membrane and reduces the risk of complications. The post-procedure observation period is also shorter and more predictable than with sedation.
From COLONOSCOPY UNDER ANAESTHESIA That is why it is now the gold standard for comfortable and safe colonoscopies.
If you also have symptoms affecting the upper gastrointestinal tract – such as heartburn, nausea or stomach pain – it is advisable to have both tests carried out at the same time. The GASTRIC AND COLONOSCOPY UNDER ANAESTHESIA It provides a complete picture of the condition of your digestive system in a single anaesthetic session, thus sparing you the need for a separate examination. If your symptoms are caused solely by your stomach, then GASTROSCOPY UNDER ANAESTHESIA is a sufficient solution.
When is a colonoscopy recommended?
A colonoscopy is not only recommended if you have symptoms. It is definitely worth having one in the following cases:
- Screening test: For the 50–74 age group, it is recommended that the test be carried out every 10 years; if the result is negative,
- Changes in bowel habits, persistent diarrhoea or constipation
- Hidden blood in the stool (positive faecal occult blood test result)
- Iron deficiency anaemia for reasons that remain unclear
- Unexplained weight loss or persistent lower abdominal pain
- Monitoring inflammatory bowel disease (IBD): In the case of Crohn’s disease or ulcerative colitis, at intervals as determined by your doctor
- Follow-up after polyp removal: In the case of high-risk polyps, the first follow-up examination is recommended 3 years after removal
When can the test not be carried out?
There are situations in which a colonoscopy is contraindicated:
- In the event of confirmed intestinal perforation
- In cases of toxic megacolon
- During the active phase of acute diverticulitis – in which case the examination is recommended 6–8 weeks after the symptoms have subsided
Possible complications and safety
A colonoscopy is a safe, routine procedure. The incidence of serious complications – such as perforation or significant bleeding – is extremely rare in diagnostic examinations, at a rate of approximately 1 in 500. In the case of therapeutic procedures (e.g. polyp removal), this rate is slightly higher, but remains below 2% overall.
Post-polypectomy bleeding may occur rarely, even 7–10 days after the procedure, when the healing tissue sloughs off. If you experience any such symptoms, seek medical attention immediately.
Endomedix’s expertise for your safety
The experienced specialists and anaesthetists at Endomedix Gastroenterology carry out every examination to the highest professional standards. The modern, professional environment and personalised patient care ensure that your examination is not only safe but also as comfortable as possible for you.
Not sure whether you need a colonoscopy? Book an appointment for a for a specialist gastroenterology consultation, where our specialist will assess your symptoms in detail and determine which test is most suitable for you.
Summary: the key points to note
A colonoscopy is a quick, safe and effective examination that can even save lives. Let’s summarise the key points:
- Duration of the study: The procedure itself takes 15–30 minutes; including preparation and post-anaesthesia monitoring, the total time spent at the clinic is 2–3 hours
- The duration is influenced by: intestinal preparation, anatomy and any therapeutic interventions
- Sleep: At Endomedix, we use only general anaesthesia, not sedation – to ensure the patient’s comfort and the accuracy of the examination
- When is it necessary: From the age of 50, as a screening test, to investigate symptoms or as a follow-up examination
- Security: a routine procedure associated with rare complications
Don’t put off your check-up! Book an appointment at Endomedix and take the first step towards looking after your health.
Frequently asked questions
How long does it take to prepare for a colonoscopy?
Preparation usually takes place on the day before the examination. On this day, you must follow a low-residue diet and then drink a laxative solution to cleanse the bowel. You must stop taking any iron supplements at least 5 days beforehand. The exact preparation protocol will always be determined by your doctor.
Is a colonoscopy painful?
During an examination carried out under general anaesthesia, the patient feels absolutely no pain. At Endomedix, we use only deep anaesthesia, so you will remain unconscious and pain-free throughout the entire procedure. After waking up, you may experience mild bloating or discomfort, which usually subsides within a few hours.
When can I eat after a colonoscopy?
After the examination, once the effects of the anaesthetic have completely worn off and the doctor has given the go-ahead, you may eat a light meal. You can usually eat on the day of the examination, but your first meal should be light and easy to digest.
Can I drive after a colonoscopy?
You must not drive a car on the day of a procedure under anaesthesia. Ask a relative or friend to accompany you to the appointment and help you get home.
When will I receive the results?
If no tissue sample was taken during the examination, the doctor will usually give you the results on the day of the examination. In the case of a biopsy or polyp removal, the results of the histological examination are usually available within 1–2 weeks.
How often should a colonoscopy be carried out?
For people at average risk, screening is recommended every 10 years if the results are negative. Following the removal of a polyp, follow-up checks are required at shorter intervals, as determined by the doctor – usually every 3–5 years. In cases of a hereditary predisposition or inflammatory bowel disease, more frequent checks are required.
