During a colonoscopy, the rectum and entire colon of patients are examined using a colonoscope, which is thin, tube-like instrument with a small camera. A colonoscope is inserted into the colon through the anus. This facilitates visual diagnosis of colorectal cancer, and a biopsy and removal of any suspicious lesion.
Pros
A colonoscopy is an important diagnostic and surveillance procedure for diagnosis of not only colorectal cancer but other gastrointestinal diseases, including inflammatory bowel disease. Screening by colonoscopy enables not only early detection of cancer in the colon and the rectum but also removal of polyps, which are precursors to cancer, according to National Cancer Institute. Polyps have the potential to grow in size and become malignant if left alone. Any polyp detected during a colonoscopy can be removed through a process called polypectomy and will be prevented to become cancer.
Cons
A colonoscopy is an uncomfortable and invasive procedure. According to the American Cancer Society, patients are often given medicine to sleep through the procedure. Use of sleep medicine may result in missing a day or more of work, and help from someone to drive you home after the procedure. Preparation for colonoscopy requires "cleaning of the bowel" using a special diet and laxatives for a day before the procedure. There are several complications associated with a colonoscopy, including perforation, bleeding and death, according to the American Cancer Society. The most common complication is perforation, occurring roughly once in every 1,000 procedures, according to a 2009 review published in "Genetics in Medicine." Death occurs in every 12,500 procedures.
Recommendation
The American Cancer Society recommends screening by colonoscopy for colorectal cancer starting at age 50, at a 10-year interval. The U.S. Preventive Service Task Force (USPSTF) recommended no colorectal cancer screening above age 75, according to AHRQ.gov. It argued the complications and cost can exceed the benefits derived from colorectal cancer screening for older people.
Significance
A colonoscopy is regarded by gastroenterologists as the gold standard of colorectal cancer screening. Although there is no randomized control trial quantifying the benefits because of colonoscopy screening, it is believed regular screening by a colonoscopy will reduce the risk of developing colorectal cancer by up to 60 percent to 80 percent, according to a review published in "Journal of American Medical Association."
Alternatives
Besides a colonoscopy, there are other less invasive options for colorectal cancer screening, including virtual colonoscopy and stool tests such as fecal immunological tests or fecal DNA, according to cancer.gov. It should be noted that a colonoscopy will be eventually used to confirm the diagnosis of cancer following a positive result from these alternative tests.
