Colorectal cancer (colon and rectal cancer) is always among the top five most common types of cancer, which is why it is so important to get screened. It is generally recommended for people to begin getting screened at age 50, or sooner if this type of cancer is in the patient’s family history.
There are a variety of tests used to screen for colon cancer or precancerous polyps, but the baseline and gold standard of detecting this cancer remains the colonoscopy. It is the single best way to detect the presence of cancerous lesions or any polyps in the colon that could turn into cancer.
Let’s talk about what you can expect for the various types of colon cancer screening tests, and how to prepare for each type of test in order to achieve the most accurate results.
Traditional Colonoscopy for Colon Cancer
Not only is the colonoscopy a diagnostic procedure – meaning that the doctor can achieve a pretty clear diagnosis from it – but it also allows the doctor to detect and remove any precancerous polyps in the colon. Each polyp that is detected can be immediately removed during the same procedure.
The patient must follow a fairly strict dietary regimen for several days before getting a colonoscopy. This is because the colon must be fully cleansed in order for the doctor to get an accurate picture of the colon, without any distractions.
This regimen used to be more difficult than it is now; gastroenterologists have developed a milder system of cleansing the colon than in prior years. Doctors were motivated to achieve a more palatable method, since the preparation actually made many patients not want to have a colonoscopy at all.
Because a colonoscopy requires general sedation during the procedure, someone else must accompany the patient to and from the exam. The patient will not be allowed to drive home themselves. (Keep in mind that many clinics also don’t allow strangers to do the driving, for the clinic’s own legal coverage and the patient’s optimum safety.)
After the colonoscopy, occasional bleeding from the rectum is possible, especially if polyps were removed during the procedure. Patients often report having cramping and bloating following the test due to the presence of air being forced up the colon.
Virtual Colonoscopy
A virtual colonoscopy uses a CT scanner to obtain cross-sections of the patient’s abdominal organs. These scans allow a doctor to detect abnormalities in the rectum or colon.
The procedure is completely noninvasive, so there is no need for sedation. However, air will be pumped into the rectum to fill the colon and make any changes easier to spot.
Because there is no direct access to the colon during this scan, if changes are detected, a regular colonoscopy will be required to examine any polyps and remove them.
Fecal Occult Blood Test
The fecal occult blood test (FOBT) and fecal immunochemical test (FIT) are lab tests performed on stool samples of a patient. Using these samples, the lab technicians can detect the presence of hidden blood.
This test can be done at home, without any preparation, and sent via the mail to the lab. However, if a patient has hemorrhoids, the test can relay false-positives – requiring that a colonoscopy then be performed in order to rule out any cancerous or precancerous lesions.
Stool DNA Test
This test is also done at home, where a stool sample is collected. There is no prep drink, sedation, or inserting of objects into the rectum.
The test checks for any changes in the DNA of cells that may indicate presence of colon cancer or precancerous lesions. This test also looks for blood in the stool; if blood is found, a colonoscopy will likely be recommended.
Flexible Sigmoidoscopy
This test involves a thin, flexible tube (sigmoidoscope) which is inserted into the rectum with a small attached camera. The doctor can then view inside the rectum and colon in a procedure that takes about 20 minutes.
Benefits include the lack of sedation, easier preparation than before a colonoscopy, and the fact that a biopsy is possible if necessary. However, the test only checks the lower portion of the colon, so any abnormal growths in the upper colon will be missed.
Gastroenterologists in Austin, Texas
If you are ready to get checked for colon cancer, contact our team at Austin Gastroenterology today. We will make your experience as seamless as possible.
Call us to request an appointment at our location nearest you, or fill out our consultation request form online – and get your colon checked.
