Colonoscopy is the definitive means of screening to detect any sort of abnormality in the colon and involves the insertion of a flexible tube into the anus with a camera attached (a CCD camera or a fiber optic camera).
This lets the doctor observe visually if there is a problem ranging from polyps, tumors, lesions and ulcerations and so on, and also gives the doctor the opportunity to perform a biopsy if required.
Here the procedure scores over X rays or ultrasounds in that therapeutic intervention can be performed right alongside.
If a person has been advised to undergo a colonoscopy, then it requires some preparation some days before hand.
Certain medications (typically aspirin or other blood-thinning medications) may be forbidden several days in advance of the procedure.
Since the colon is required to be clear in anticipation of the procedure, the person is advised only to have clear liquid and low fiber foods.
Water, sports drinks, certain clear juices, clear broths of chicken or beef, and so on are allowed to be had and considerable list of items, particularly fibrous and highly colored items are barred.
It is important to keep hydrated since enemas, laxatives and similar procedures can cause dehydration and electrolyte imbalance.
A laxative is administered the day before in order to clear the bowel of all fecal matter. In the alternative whole bowel irrigation is performed. It is best to spend this day at home or any place with immediate access to the bathroom.
When the procedure is to be performed, the patient is made to lie on their side with the knees drawn up the chest and sedated and not anesthetized.
In a colonoscopy, the colonoscope is inserted into the anus and up along the full extent of the colon, unlike the sigmoidoscopy, which examines only one third of the colon. The area is inflated with air to provide a better view.
During the procedure, suction may be required to extract secretions, photos of the insides of the colon may be taken, polyps may be removed and if required a biopsy may be performed to extract any tumor like matter to examine for malignancy.
Some practitioners use music during the procedure since it has been shown to improve pain tolerance by the patient. Rather than at the time of the insertion of the scope, the time of withdrawal is when the more important internal examination takes place.
Depending upon the individual, the findings and the indications, the procedure can take between 20 and 30 minutes.