Test Preparation How It Works Accuracy Screening Interval
Colonoscopy Complete or partial bowel cleansing before procedure. Some form of sedation is used in most centers. In a specialist's office, a scope is used to look at the whole length of the colon. Cancer can be seen, and sometimes removed, during this procedure. Greater than 95% accurate. Accuracy depends on the experience of the person doing the exam. This is the “gold standard” test. Colonoscopy is the follow-up for positive results on other screening tests. Every 10 years
Computed tomographic colonography (virtualcolonoscopy; CTC) Complete bowel cleansing and inflation of the colon with gas.  A small rectal catheter is used to fill the colon with air to get clear CT scan pictures. Up to 94% detection rate for large polyps. Every 5 years
Double-contrast barium enema (DCBE) Complete bowel cleansing and barium sulfate, nflation of the colon with gas. Typically no sedation. A small rectal catheter is used to fill the colon with air to get a clear X-ray of the colon. Detection rate is from 85-97% and up to 73% for adenomas. Accuracy depends on bowel prep and the experience of the person doing the exam. Every 5 years
Flexiblesigmoidoscopy(FSIG) Complete or partial bowel cleansing prior to procedure. Typically no sedation. In a specialist's office, an endoscope is used to look at the lower part of the colon. Highly accurate in diagnosing colon cancer in the lower colon. Accuracy depends on the experience of the person doing the exam. Every 5 years
Fecalimmunochemicaltest (FIT) None Collect a stool sample at home from the toilet bowl or toilet paper, using a special tool. If the lab finds blood in the sample, it may signal cancer. Detection rate is up to 65%. Once a year
Fecal occultblood test(FOBT) Requires a special diet and avoidance of some medications. Collect multiple stool samples at home. Requires placing the stool sample on a card. If the lab finds blood in the sample, it may signal cancer. Many kinds of this of test are available. Detection rates vary from 9-64%.  Once a year
Stool DNA test None A stool sample is collected using a toilet insert. cells from the colon shed into the stool are examined for a DNA marker associated with colon cancer. Detection rate is 77%. Every 3 years