Cancer of the Large Intestine

Symptoms

Symptoms of colorectal cancer include:

• blood on the rectum or in the stool
• feelings of fecal urgency (feeling as if one has to have a bowel movement all the time)
• stomach and/or abdominal pain
• changes in bowel habits, including constipation, diarrhea, and/or pencil-thin stools
• extreme fatigue
• decreased appetite

Diagnosis

The simplest screening tests for colorectal cancer include a digital rectal exam and a fecal occult blood test (FOBT). In the digital rectal exam, a physician inserts a gloved finger into the rectum and feels for any irregularities. In the FOBT, stool samples are tested for traces of blood. The test can be done at home and sent to a lab for analysis. FOBT can reduce the death rate by about 33%. Unfortunately, in the United States, over the past six years less than 35% of the population had received a FOBT.

A flexible sigmoidoscopy and/or a colonoscopy may be performed to view the interior of the colon. The former examines the rectum and lower colon for cancer, and the latter examines the full length of the colon. During these procedures, a doctor passes a flexible tube with a

tiny, fiber-optic camera device (an endoscope) through the rectum and into the colon. The doctor can carefully examine the lining of the intestine for signs of cancer. A tissue sample (a biopsy) of the colon also can be taken through the endoscope to examine under a microscope for evidence of malignancy. Both tests can cause discomfort, and may be done under a local anesthetic if desired.

A lower GI (gastrointestinal) x-ray series can be helpful in determining how much of the intestine is involved in the disease. A chalky solution called barium, which acts as a contrast agent to illuminate the gastrointestinal tract on x-ray film, is administered in enema form to the patient. In some cases, air also is pumped into the rectum to provide a clearer view of the large intestine. This is called a double-contrast barium enema. The pressure in the patient's abdomen from the air and barium contrast likely will cause some discomfort.

After colorectal cancer is diagnosed, further testing is required to determine how far the cancer has spread. This procedure is known as staging. There are five different stages of colorectal cancer:

• Stage 0 (carcinoma in situ). This is the earliest stage of colorectal cancer, and indicates that cancerous cells have not spread beyond the colon lining.
• Stage I. The cancer has spread to the second and third layers of the inside wall of the colon, but is still contained within the colon.
• Stage II. The cancer has spread beyond the colon, but has not spread to the lymph nodes.
• Stage III. The cancer has spread to a nearby lymph node, but has not spread throughout the body.
• Stage IV. The cancer has spread throughout the body.

There is a sixth subtype of cancer, called recurrent, which is used to classify colorectal cancer that was treated, seemed to resolve, and has now recurred either in the colon or in another part of the body.

Content
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Author Info: Paula Ford-Martin, Teresa G. Odle, The Gale Group Inc., Gale, Detroit, Gale Encyclopedia of Alternative Medicine, 2005

This feature is for informational purposes only and should not be used to replace the care and information received from your healthcare provider. Please consult a healthcare professional with any health concerns you may have.