Diagnosing bowel cancer through colonoscopies?

Each year in Switzerland, around 4,100 people die of bowel cancer. Also, 1,600 people die from the after-effects of the disease. Is it worth having a colonoscopy as a form of cancer screening? We provide the information so you can make up your mind.

24.01.2023 Tanja Kühnle 2 minutes

In order to detect and treat bowel cancer at an early stage, an examination of the large bowel, known as a colonoscopy, is offered in Switzerland. Unfortunately, there is still no reliable information available on the possible benefits and adverse effects of this examination procedure. However, long-term medical studies are already being carried out and are expected to start producing results over the next few years.

Alternatively – and this has not been particularly commonplace in Switzerland so far – a sigmoidoscopy, which only looks at part of the colon, is another option that can be considered as an early detection method. A flexible sigmoidoscopy examines the last 60 centimetres or so of the colon with an endoscope. This makes it possible to detect bowel cancer or its very early stages and remove it at the same time – even before symptoms start to appear. This type of procedure may also cause pain and complications, however.

For this reason, there is no definitive answer as to whether or not a sigmoidoscopy is always a sensible option. The Harding Center for Risk Literacy at the University of Potsdam has summarised the potential benefits and adverse effects of the sigmoidoscopy based on the available scientific studies.

The medical evidence

Long-term studies looked at groups of people over 50 years of age who did or did not participate in screening by means of a sigmoidoscopy. After ten years, the participants and non-participants were compared.

Across both groups, 254 out of 1,000 people died. In the group that did not undergo a sigmoidoscopy, 8 out of 1,000 people died from bowel cancer. In the group that underwent a sigmoidoscopy, this figure was 6.

Among the non-participants, 20 out of 1,000 people were diagnosed with bowel cancer. In the screened group, this was the case for 16 out of 1,000 people.

What are the risks of a sigmoidoscopy?

During the sigmoidoscopy, 200 out of 1,000 people experienced medium to severe pain. Serious complications such as bowel injury and bleeding affected fewer than 1 out of 1,000 participants.

A sigmoidoscopy may well help to reduce the number of people who die from bowel cancer. By removing bowel cancer’s initial stages during the endoscopy, bowel cancer diagnoses were prevented in 4 out of 1,000 people. Many of the participants suffered from pain, however, and a few individuals from further complications.

In light of these facts, there is no definitive answer as to whether or not to opt for a sigmoidoscopy as a form of bowel cancer screening. Everybody must ultimately decide for themselves. We hope you now have an overview of this complex issue.

Do you have any other questions?

Do you have any questions about about a diagnosis you have received? Or would you like to know about other health-related issues? Our health advisors provide you with helpful information and specific recommendations.

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