A flexible sigmoidoscopy might also be required or
suggested for a screening test. A flexible
sigmoidoscopy is an examination of the lower part
of the gastrointestinal tract called the colon or large
intestine. It is performed by an endoscopist, who is a
doctor or other health professional with special
training in endoscopic procedures. There are several
reasons that flexible sigmoidoscopy may be
recommended, with one of the most common
reasons being the need to screen for colon cancer in
people older than 50 years of age. A more advanced
exam called a Computed tomography colonography
is also made available in today’s hospitals.
Computed tomography (CT) colonography is a test
that uses a CT scanner to take images of the entire
bowel. These images are in two- and threedimensions, and are reconstructed to allow a
radiologist to determine if polyps or cancers are
present.
Colon cancer affects the large intestine in the body.
The large intestine is the terminal portion of the
intestine and consists six parts: 1) the caecum, 2)
ascending colon, 3) transverse colon, 4) descending
colon, 5) sigmoid colon, and 6) rectum. Colon
cancer can affect any of the above mentioned parts
and the symptoms differ depending upon the
location of the cancer. The colon and the rectum are
the final portions of the tube that extends from the
mouth to the anus. Food enters the mouth where it is
chewed and then swallowed. It then travels through
the esophagus and into the stomach. In the stomach,
the food is ground into smaller particles and then
enters the small intestine in a carefully controlled
manner. In the small intestine, final digestion of food
and absorption of the nutrients contained in the food
occurs. The food that is not digested and absorbed
enters the large intestine or colon and finally the
rectum. The large int