A lot of information about colonoscopy can be found at the Bowel Cancer Australia website.
Colonoscopy is a means to look inside the large bowel from the appendix to the anus to look for evidence of disease.
It does not cover the small bowel or the stomach.
Most commonly colonoscopy is used when there are symptoms that may suggest bowel cancer.
Screening for Bowel Cancer
Colonoscopy is sometimes suggested as a routine screening procedure to prevent cancer of the bowel. However, the Australian government provides a free screening program for bowel cancer that only uses colonoscopy IF blood is detected in the stools by a preliminary test.
Other Bowel Diseases
Colonoscopy is also used to explore the cause of unexplained changes in bowel habits, evaluate symptoms of pain or bleeding located in the abdominal area or find a reason for weight loss, chronic constipation, or diarrhea.
It can help detect a range of non cancer conditions diseases such as diverticulitis, ulcerative colitis etc.
The recommended frequency of colonoscopy for detecting bowel cancer varies according to the risk. The risk is based on family history of the disease inclose relatives or in having a pre-existing condition that is known to increase the risk of bowel cancer.
Your doctor will take a history and assess whether you need a more frequent screen using colonoscopy than the general public.
Cancer Council of Australia publishes guidelines on frequency of colopnoscopy depending on individual risk..
For Bowel Cancer screening:
Information about the frequency of colonoscopy is also available from the College of General Practitioners.
Small polyps grow slowly and may take 10 years or longer (if at all) to develop into bowel cancer. For this reason, it is considered inappropriate to continue screening in people aged over 75.
International speciality groups don't recommend ongoing screening when life expectancy is less than 10 years, because many people will not benefit. And they will be exposed to the risks of colonoscopy, including bowel perforation and major bleeding.
Australian guidelines also recommend stopping colonoscopy in people aged around 75.
In young people, colonoscopy is often performed to look for inflammatory bowel disease, but new non-invasive stool tests can select out people at higher risk.
Young people with irritable bowel syndrome may also undergo repeated colonoscopies to try to find an alternative reason for their symptoms, but this strategy is usually unhelpful.