Colonoscopy The colonoscopy is an examination of the colon or large intestines. It is a screening exam for adults over the age of 50 for colon and rectal cancer. It is also indicated for the evaluation of bowel disorders, rectal bleeding or polyps that are identified on x-ray studies. Bowel preparation is required prior to the procedure. Patients are often given IV medication for pain and sedation to relax them and relieve anxiety. The procedure lasts from 30 minutes to 1 hour. The colonoscopy is performed by a gastroenterologist using an instrument known as a colonoscope. The colonoscope is a long and flexible fiber optic instrument equipped with a light and lens. This allows the physician to look inside the large intestines and take a small sample called a biopsy if indicated. The initial colonoscopy maybe called a screening colonoscopy. All colonoscopies performed after the screening exams are called diagnostic colonoscopies if the findings are normal. If the physician finds a polyp or a suspicious area that needs to be biopsied, this can be done during the colonoscopy procedure. There are several ways to biopsy or remove a polyp. A cold biopsy is used when the physician takes tissue samples in different areas of the colon without the use of electric current. Polypectomy by snare technique is another biopsy method in which the physician uses a heated wire loop to shave the polyp off. A polypectomy by hot forceps technique captures polyps within the colon and cauterizes the area to prevent bleeding. All tissues removed are sent for pathological examination. Patients should consult their physician for a complete explanation of the procedure and its associated risks and complications.