is the visual examination of the inside of the rectum and sigmoid colon
using a lighted, flexible fiberoptic or video endoscope. The colon, or
large intestine, is 5 to 6 feet long. During a sigmoidoscopy, only the
last 1 to 2 feet of the colon is examined. This last part of the colon,
just above the rectum, is called the sigmoid colon.
FOR THE PROCEDURE
is performed to diagnose causes of symptoms or as a preventative measure
to detect problems at an early stage before they are even apparent to
bleeding is very common. It often is caused by hemorrhoids or a small
tear at the anus, called a fissure. However, more serious problems can
cause bleeding. Benign polyps can bleed. It is important to identify and
remove polyps at an early stage before they become malignant. Rectal and
colon cancers bleed and require immediate diagnosis and treatment. Finally,
various forms of colitis and inflammation can cause bleeding.
- Persistent diarrhea should always be evaluated by Sigmoidoscopy There
are many causes of diarrhea and the exam is of great help in tracking
down the specific cause.
Pain - Hemorrhoids
and fissures are some causes of pain around the anus or in the rectum.
Discomfort in the lower abdomen can be caused by tumors as well as diverticuli.
This condition is called diverticulosis. Small pockets or sacks project
from the bowel in this condition.
- A barium enema x-ray exam may show abnormalities that need to be confirmed
or treated by Sigmoidoscopy
- Colon cancer is the most common cancer in this country. it is highly
curable if it is found early. This cancer may begin in the colon as a
polyp that remains benign for many years. Therefore, it is generally advisable
to have a surveillance exam after age 40. If there is a history of
colon polyps or cancer in parents or siblings, it is even more critical
to have this exam because there is a definite hereditary aspect of colon
the full benefits of the exam and allow thorough inspection, the rectum
and sigmoid colon must be clean. Preparation usually involves drinking
clear liquids the day before along with taking enemas and/or laxatives.
Specific instructions for preparation are always given by the physicians
sigmoidoscopy is performed on an outpatient basis, usually in the doctor's
office. It performed with the patient lying on the left side with the
legs drawn up. A sheet is placed over the lower body. A finger or digital
exam of the anus and rectum is performed. Then the sigmoidoscope is gently
inserted into the rectum. Air is inflated into the bowel to distend it
and allow for careful examination. The patient usually feels this distention
of the rectum. The scope is then advanced under direct vision and moved
around the various bends in the lower bowel.
is advanced as far as possible without causing undue discomfort. When
possible, the exam is continued to 25 inches (60 cm). Certain conditions,
such as diverticulosis, irritable bowel syndrome or prior pelvic surgery,
may produce discomfort when the sigmoid colon is entered by the scope.
The exam is stopped if this occurs. The entire exam usually takes only
5 to 10 minutes. Sedation is not normally required.
of Sigmoidoscopy are considerable. A specific diagnosis can often be made.
A condition, such as colitis, can be monitored following treatment. Polyps
and tumors can be discovered at an early stage.
testing includes barium enema X-ray exams. Additionally, the stools can
be examined in a variety of ways to uncover or study certain bowel conditions.
However, direct visualization of the lower rectum and lower bowel is by
far the best method of examining this area.
and bowel distention are common due to the air inflated into the bowel.
This usually lasts only 30 to 60 minutes. If biopsies are done or if a
polyp is removed, there may be some spotting of blood. This is rarely
ever serious. Other very uncommon risks include a diagnostic error or
oversight, or a tear (perforation) of the wall of the colon which might