What is a colonoscopy?

A colonoscopy, often also called a bowel examination, is the procedure in which a doctor examines the large bowel using a colonoscope. During the examination, air or a special gas is passed into the bowel so that the bowel walls open up and become easier to see. Where there are unusual areas, a small tissue sample can be taken. This is done through a small working channel inside the colonoscope. If non-cancerous growths, known as polyps, are found, they can be removed straight away. A colonoscopy is especially important for finding possible causes of blood in the stool, ongoing stomach pain, or long-lasting diarrhoea.

Why is a colonoscopy carried out?

A colonoscopy helps doctors find out why certain digestive problems are occurring that cannot be explained on their own. These include pain in the lower abdomen, sudden changes in bowel habits, or diarrhoea that goes on for a long time. Even more importantly, a colonoscopy plays a key role in the early detection of bowel cancer. Cancerous tumours often develop slowly from polyps that are harmless at first. These can be found and removed during a timely colonoscopy, before they cause symptoms or become cancerous.

Preparation and procedure

Good preparation is essential for a colonoscopy. Your bowel must be completely empty so that the doctor has a clear view and nothing is missed. A special drinking solution is often taken to clean the bowel, and a particular diet is followed for a limited period of time. On the day of the examination, you will usually be given a sedative or a short-acting sleeping medication so that you can relax. Some people even fall asleep during the procedure and are not aware of anything at all. After the colonoscopy, you will stay for a short time to be observed, so that you feel well enough before going home.

Risks and side effects

A colonoscopy is generally safe, but like any medical examination, it can carry certain risks. This mainly concerns bleeding, for example when tissue samples or polyps have been removed. Injury to the bowel wall is also possible, though rare. People with existing health conditions or who are older may additionally react to sedatives or pain relief, or may develop cardiovascular problems. In extremely rare cases, infection can occur through the transfer of germs. People over the age of 75 should carefully weigh up, together with their doctor, whether the benefits outweigh the risks.

When should you consider a colonoscopy?

Recommendations for bowel examinations are based mainly on your age and your personal level of risk. Many specialists advise men to have a regular colonoscopy from the age of 50, while women are usually entitled to a screening examination from the age of 55. However, if there have been cases of bowel cancer in your family, or if you have a chronic inflammatory bowel condition, it may be worth having a colonoscopy earlier. If you notice blood in your stool or an irregular pattern of switching between diarrhoea and constipation, it is advisable to speak to your doctor regardless of your age.

Alternatives to colonoscopy

Sometimes different examination methods can be considered as an alternative to a standard colonoscopy. A virtual colonoscopy using computed tomography creates a three-dimensional image of your bowel without inserting a tube. Capsule endoscopy is another option, where you swallow a small camera in the form of a capsule. The immunological test for traces of blood in the stool is also frequently recommended, especially for routine screening. It is less involved, but does not show all possible changes as precisely as a real colonoscopy. For an overview of the lower part of the large bowel, a sigmoidoscopy may sometimes be considered, though it does not cover all sections of the bowel. If these alternatives show anything unusual, a full colonoscopy is in many cases still necessary, because it provides the most reliable results.

Recommended age limits for screening examinations

A regular colonoscopy is usually recommended for men from the age of 50 and for women from the age of 55, to protect against bowel cancer. Those with a higher risk, for example due to certain genetic changes or close family members with bowel cancer, are best advised to start examinations earlier. You should also always speak to a doctor if you have symptoms such as blood in the stool, sudden weight loss, or persistent stomach pain, to find out whether a colonoscopy or another examination is appropriate. Once you have a report or medical letter that mentions a bowel examination or the use of a colonoscope, you can discuss any open questions with your doctor. It is important that you do not feel afraid to raise your own symptoms and concerns. That is the only way to judge whether and when the next examination should take place.