Colon Cancer Diagnosis
Colon cancer is a condition that will often not show symptoms until it is at an extremely advanced stage, which means that many patients are unaware that they have the disease. Therefore, it is your responsibility to attend regular appointments with your colorectal specialist so that you can be screened periodically for signs of developing conditions, as necessary.
Diagnosis by Regular Screenings
If you are identified as having a high risk of developing colon cancer, then your Los Angeles colorectal surgeon will encourage you to attend regular screening sessions. The most accurate method of screening for colon cancer is by a regular colonoscopy, which allows the doctor to assess the lining of your colon for any abnormalities. You will be advised how often a screening will be needed depending upon your specific risk factors and age.
A colonoscopy procedure involves the insertion of a narrow, flexible tube into the colon through the anus. The tube has a camera on the end, sending images to a computer screen in the examination room. The doctor examines the lining of your entire colon, rectum and anus, looking for any abnormal growths, known as polyps, which are not dangerous at the precancerous stage. However, if polyps remain for a considerable length of time, they may gradually turn cancerous. For this reason, it is advisable to have polyps removed as soon as they have been seen. Polyps can be removed during a colonoscopy screening procedure, so you do not need to book another appointment and undergo further treatment. Once a polyp has been removed, it typically does not grow back in the same location, although others can develop, which is why regular screening is necessary.
Diagnosis by Virtual Colonoscopy
Some colorectal surgeons are now offering regular screenings of the bowel by virtual colonoscopy, rather than the more invasive colonoscopy procedure. This has a number of advantages over any other screening methods. It uses a CT (computerized tomography) scan to produce a 3D image of the colon, which can then be displayed on a computer screen. No sedation is required and the procedure is completely non-invasive. A virtual colonoscopy is considerably quicker to perform than a traditional colonoscopy, taking approximately ten minutes.
However, you will still need to go through the same bowel preparation as you may have done for a colonoscopy since the CT scan will only produce a clear image if the bowel is empty. This is likely to involve taking laxatives for several days before your scan as well as eating a restricted diet that concentrated in fiber.
While virtual colonoscopy is considerably more comfortable, it is less accurate and reliable. Some polyps may not always be identified on the scan, making it necessary to undergo a repeat procedure. Growths cannot be removed during a virtual colonoscopy, so if they are identified, you will need to have a colonoscopy in order to remove them. Your colorectal surgeon will discuss the most appropriate screening method for you at your consultation.
Diagnosis by X-rays of the colon
X-rays of the colon can also be used to identify any abnormalities. A CT scan uses X-rays, and then these are usually compiled into a detailed 3D image of the colon. A barium enema involves insertion of a dye in the form of an enema to fill the colon and look for irregularities in the lining. This procedure also requires a bowel cleanse prior to the procedure. Small lesion or polyps may be missed and if a polyp is found, then a repeat bowel preparation followed by colonoscopy to remove or biopsy the lesion will be required.
What the doctor does during diagnosis
The doctor will be performing the screening procedure, and this will vary according to the method that has been chosen. However, in all cases, the doctor is examining the lining of the colon for the presence of polyps, and if you are having a colonoscopy or a flexible sigmoidoscopy, they may also take some biopsies. This involves removing a small sample of the tissue from the colon so that it can be checked for any cancerous mutations. Polyps can be removed during a colonoscopy or sigmoidoscopy, but not during any other form of screening procedure.