Colorectal Cancer Screening

Colorectal cancer remains the second leading cause of U.S. cancer fatalities, with nearly 50,000 deaths annually. It also is one of the most avoidable types of cancer.

Up to 90 percent of colon and rectal cancers can be prevented through lifestyle changes and the early detection and removal of precancerous polyps and early stage cancers — often long before any symptoms appear.

UC Irvine Health polyp detection rates are among the highest in the nation. Our gastroenterologists are among the most experienced at performing colonoscopies safely and painlessly.

Call our experienced UC Irvine Health colorectal diseases team today at 844-824-2656 to schedule your colorectal cancer screening test.

Who should be screened?

Men and women beginning at age 50 should follow one of these regimens:

  • An annual stool test
  • An imaging test or a sigmoidoscopy every five years
  • A colonoscopy every 10 years

People should begin screening earlier and more often if they have these colorectal cancer risk factors:

  • A strong family history of colorectal cancer or polyps, especially in a parent or sibling who developed the condition before age 45, or in two first-degree relatives of any age
  • A family with hereditary colorectal cancer syndromes, such as familial adenomatous polyposis and hereditary nonpolyposis colon cancer
  • A personal history of colorectal cancer or adenomatous polyps
  • A personal history of chronic inflammatory bowel disease (Crohn's disease or ulcerative colitis)

How do you screen for colorectal cancer?

Several methods are used to detect colorectal cancers, including:

  • Fecal occult blood test (FOBT) checks for microscopic blood particles in the stool. A tiny sample of stool is swabbed on a special card(s), which is sent to a laboratory. Avoiding drugs (aspirin, ibuprofen and other anti-inflammatory agents) or food that may irritate the bowel is required before testing.
  • Fecal immunochemical test (FIT) is similar to the FOBT, but requires no diet or medication restrictions before testing.
  • Flexible sigmoidoscopy allows the physician to examine the lower third of the large intestine with a small video camera contained in a short, flexible tube that is inserted through the rectum.
  • Barium enema with air contrast (also called a double contrast barium enema) involves pumping a chalky liquid called barium into the rectum to coat the bowel, followed by air to expand the rectum and colon. An X-ray of the abdominal area can then display any narrowing, blockages or other problems.
  • CT colonography (virtual colonoscopy) is a noninvasive imaging procedure using computerized tomography (CT) to scan the colon. Images are used to create a 3D-model of the colon along with any polyps or masses. Although a virtual colonoscopy is noninvasive, a small tube is inserted into the rectum to pump air into the colon for more accurate imaging.
  • Colonoscopy allows the physician to view the entire large intestine through a long, flexible tube similarly equipped with light and a video camera and also inserted through the rectum. The colonoscope enables the physician to see any abnormal growths, inflamed tissue, ulcers or bleeding in the colon walls, and to remove precancerous polyps or sample tissue for further examination. View a video of a colonoscopy procedure ›

How do I choose a screening test?

Each has advantages and disadvantages. All screening tests help to find colorectal cancers before symptoms develop. Only colonoscopy helps prevent colorectal cancer. Your choice depends on personal preferences and goals.

Early detection

FOBT and FIT are simple self-administered tests that can be sent to a lab. If either test is positive, a colonoscopy is usually required.

Sigmoidoscopy views only the lower one-third of the colon, missing about 50 percent of polyps and cancers. Barium enemas and virtual colonoscopies can help detect abnormalities along the entire bowel. All three procedures, like the stool tests, require follow-up with a standard colonoscopy for accurate diagnosis.


Colonoscopy combines the best method for finding polyps and early colorectal cancers. It is also the only screening test that allows the physician to identify and remove precancerous polyps before colorectal cancer develops. That is why colonoscopy is considered the “gold standard” of colorectal cancer testing.

A colonoscopy does require some advance preparation to cleanse the bowel, but the procedure is relatively simple, usually painless and performed on an out-patient basis.

Regular colonoscopy screenings have resulted in a reduction in colorectal cancers of more than 70 percent and lowered colorectal cancer deaths by more than 50 percent.

For more information or to schedule a colorectal screening appointment, please call 844-824-2656.

UC Irvine Health The Anti-Cancer