by Katie Lee

Created on: April 25, 2008   Last Updated: April 29, 2008

A colonoscopy is a procedure that allows doctors to see inside a person's colon, which is the large intestine or bowel, and is located in the lower part of the abdomen. The colon stores unabsorbed food waste and water before it is eliminated from the body as stool. Commonly, a colonoscopy is used to detect early signs of colon cancer, but in cases where a person is suffering from gastrointestinal maladies, it is also a way for doctors to look inside the gastrointestinal tract to see what the problem might be. Generally, a colonoscopy is recommended for anyone over the age of 50 as a routine screening for colon cancer.

Before the colonoscopy, there is some preparation that must be done. The colon must be emptied and cleansed so as to provide an unobstructed pathway for the colonoscope (a small, lighted, flexible tubing with a camera attached to its tip). Instructions may vary depending on each person but generally, most will be asked to go on a clear liquid diet approximately 1-3 days before the scheduled procedure. Some may be asked to take a laxative or give themselves an enema to purge the bowel. Some may have to drink a special undigestible solution like GoLytely, which can taste very unpleasant. For those who take certain medications, they may need to stop the medications temporarily to decrease any risk of bleeding or complications.

During the procedure, the patient lies on their side and is given a mild sedative as well as a narcotic painkiller to minimize any discomfort during the procedure. Some patients will be awake but unaware, while others will be asleep depending on their reactions to the sedative. The patient's vitals (pulse, blood pressure, oxygen level) will be monitored throughout the procedure. The doctor will then insert the colonoscope into the rectum and slowly guide it into the colon, where the doctor will then examine the colon, via images transmitted by the camera mounted at the tip. If necessary, the doctor can also remove any polyps or take a tissue sample (biopsy) while conducting the colonoscopy.

The procedure normally takes about an hour. Because air was pumped through the colon to allow the colonoscope to move through it, patients may feel mild cramping and bloated afterwards. Patients must remain under observation until the effect of the sedative has worn off, and should expect to not return to their job or other activity for the rest of the day. They can resume their diet after the procedure, but should consult with their doctors about starting up any medications again.

A colonoscopy is generally a very safe procedure, but like any medical procedure, there can be complications. Though rare, bleeding due to the removal of polyps or biopsies can occur, and some patients may have an adverse reaction to the sedative they are given. Thus, patients should report any rectal bleeding, vomiting, fever or severe abdominal pain. Generally, however, most patients feel fine after the procedure, and a colonoscopy is a relatively easy and effective way to detect and treat serious gastrointestinal disorders.

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