According to the National Institutes of Health, colonoscopies are tests that enable gastroenterologists to examine the colon for abnormalities such as colon cancer, colon polyps, ulcerations and areas of inflammation and bleeding. Colonoscopies are used to diagnose bowel disorders such as inflammatory bowel disease, ulcerative colitis and Crohn's disease. Colonoscopies are also used to assess for the causes of abdominal pain, unexplained weight loss and bloody stool. There are different types of colonoscopy procedures.
Conventional Colonoscopy
According to the National Institutes of Health, conventional colonoscopy is the most frequently used procedure to diagnose colon cancer and other colon abnormalities. Conventional colonoscopy involves the use of a flexible fiber-optic tube known as a colonoscope to directly examine the colon. A colonoscope is inserted into the anus and advanced to the end of the colon. The gastroenterologist then slowly removes the colonoscope while examining the walls of the colon for any abnormalities. During conventional colonoscopy, the doctor may remove polyps, conduct a biopsy or use heat treatment to seal bleeding blood vessels.
Virtual Colonoscopy
The National Institutes of Health states that a virtual colonoscopy is computerized tomographic scanning of the entire colon. A tube containing air is inserted into the colon. Air is pumped until the colon is inflated. Images of the colon are obtained using computerized tomographic scanning. A computer is used to magnify the images and create a three-dimensional view of the colon. Virtual colonoscopy is not a direct visualization of the colon. Patients who are noted to have colon abnormalities during virtual colonoscopy require conventional colonoscopy to remove the abnormalities.
Flexible Sigmoidoscopy
According to the National Institutes of Health, flexible sigmoidoscopy is similar to a conventional colonoscopy, except that only the lower part of the colon is examined. A flexible tube also known as sigmoidoscope is used to examine the sigmoid colon, which is the lowest part of the colon. Flexible sigmoidoscopy misses abnormalities in the upper parts of the colon.
