Colonoscopy and Colon Cancer

Colonoscopy and Colon Cancer

The colon, also called the large intestine, is the final section of the human digestive system, where water, salts and some nutrients are absorbed into the body leaving behind waste in the form of stool. Colorectal cancer occurs when cells in the colon or rectum divide uncontrollably, creating a malignant tumor.

Colorectal cancer usually begin as a growth, called a polyp which is located in the inner surface lining of the colon or rectum. Polyps can take a variety of forms and are flat, raised like mushrooms without stalks, or raised like a mushrooms with stalks. Not all polyps are cancerous; it is common for people older than 50 years of age to be diagnosed with non-cancerous polyps.

Colorectal cancer is one of the most common kinds of non-skin cancer and is also the second most common cause of cancer death in the United States.

Several tests have been developed to detect early signs of colorectal cancer. It is best to find and treat cancer early for a higher chance of successful treatment. Some tests can also actually prevent cancer development because the tests allow for the detection and total removal of possible cancer growths.

Colorectal Cancer Screening

High-sensitivity fecal occult blood tests (FOBT)

Polyps and colorectal cancers can bleed. FOBT checks for tiny amounts of blood in feces that cannot be seen. Not all blood in feces is a symptom of polyps or cancer, and can be an indicator of hemorrhoids. FOBT requires a stool sample to be collected by the patient using a special kit, which is then given to the doctor.

Some advantages and disadvantages of a colorectal cancer screening are as follows:


  • No cleansing of the colon is required.
  • No sedation.
  • Samples can be collected at home.
  • No risk of damage to colon lining.
  • Lower cost than other cancer screening tests.


  • The test may not detect all polyps and cancers.
  • False-positive test results are also possible.


A sigmoidoscope is a flexible tube with a light, lens for viewing and a tool for tissue removal. The rectum and sigmoid colon can be examined using a sigmoidoscope. The sigmoidoscope is inserted through the anus into the rectum and colon while air or carbon dioxide is pumped into the colon. The air is used to expand the rectum and colon, making it easier to view the colon lining. During sigmoidoscopy, growths in the rectum and colon can be biopsied or removed for analysis. Patients are usually not sedated for a sigmoidoscopy, and preparation for the procedure only requires the lower colon to be empty. This means that preparation for a sigmoidoscopy is less aggressive than for a colonoscopy.

Some advantages and disadvantages of a sigmoidoscopy are as follows:


  • For most patients, discomfort is minimal.
  • Sedation is usually not required.
  • Complications are rarely encountered.
  • Polyps can be removed during the test.
  • Less extensive colon cleansing than for a colonoscopy.


  • The test only allows the doctor to view the rectum and lower colon, so polyps and cancer in the upper part of the colon can be missed.
  • Bowel cleansing is required before the test.
  • Medication and diet changes may be necessary before the test.
  • Very small risk of bleeding, tearing or perforation of the colon lining.

Standard Colonoscopy

Also called optical colonoscopy, is a test in which the doctor examines the tissue of the colon and rectum with a colonoscope. A colonoscope is a flexible tube with a light, lens for viewing, and a tool for tissue removal. Colonoscopy is similar to sigmoidoscopy in that the scope is inserted through the anus into the rectum and the colon while air is pumped into the colon to expand. This allows the doctor to clearly view the colon lining. Abnormal growths in the colon and rectum can be removed during the procedure. In preparation for this test, some form of sedation is usually required along with a thorough cleansing of the entire colon.

Some advantages and disadvantages of a colonoscopy are as follows:


  • The most accurate test available.
  • The doctor can cut out polyps or growths during the procedure if necessary.


  • Though this test is very accurate, it still may not detect everything.
  • Thorough colon cleansing is required before the test.
  • Diet changes are required before the test.
  • Some form of sedation is almost always required.
  • There is a small chance of bleeding, tearing or perforation of the colon lining.

Which Treatment is Right for You?

Several factors such as your medical and family history should be taken into account when deciding which test to undergo. To determine which treatment is right for you, contact Dr Gabriel Akopian at West Coast Colorectal and our staff today. Serving Pasadena and Southern California, we are committed to providing our clients with the best medical care. Questions? Call us at: 626-716-9892

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Gabriel Akopian, MD
10 Congress Street, Suite 300
Pasadena, CA 91105

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