Colonoscopy

A colonoscope is a long, flexible tube that is approximately the thickness of a finger. It is inserted through the rectum into the large intestine (colon) and allows the doctor to carefully examine the lining of the colon. Abnormalities of the colon can be seen in great detail. If the doctor sees a suspicious area or needs to evaluate an area of inflammation in greater detail, he can pass an instrument through the colonoscope and take a small piece of tissue (biopsy) for examination in the laboratory. Biopsies are taken for many reasons and do not necessarily mean that cancer is suspected.

Indications for colonoscopy:

• blood in the stool or rectal bleeding
• dark/black stools
• persistent diarrhea
• anemia
• weight loss associated with gastrointestinal symptoms
• family history of colon cancer
• abnormal imaging studies such as CT scan or barium enema
• previous history of colon polyps or cancer
• surveillance for inflammatory bowel disease
• chronic unexplained abdominal pain

In a small percentage of cases, passage of the colonoscope through the entire colon cannot be achieved. A limited examination may be sufficient if the area of suspected abnormality was well visualized. In addition, other imaging studies may complement colonoscopy when this rare situation arises.