A colorectal screening is a test that detects abnormal growths (cancerous and non-cancerous) in a patient's rectum or colon, according to the Centers for Disease Control and Prevention. Patients, age 50 and older, should participate in regular colorectal screening tests, states the American Cancer Society.
As of 2015, patients may choose from six colorectal screening tests. The frequency of each test, along with the length of time each test takes, may vary. A colonoscopy lasts about 60 minutes and should be performed every 10 years, reports Mayo Clinic. This colorectal screening test can detect tiny polyps (abnormal growths) in both the rectum and colon. During the procedure, physicians can also retrieve tissue samples for further testing.
A virtual colonoscopy typically takes about 10 minutes and should be performed every 5 years, according to Mayo Clinic. A flexible sigmoidoscopy lasts about 20 minutes and should be repeated every 5 years, states the American Cancer Society.
The fecal occult blood test, the fecal immunochemical test and the stool DNA test, are usually performed annually, according to the American Cancer Society. Unlike the other three colorectal screening tests, these tests allow patients to collect stool samples at home and give the samples to a physician's lab for testing.