Doctors say those figures are smaller than the proportion of women who get mammograms for breast cancer or men who have the PSA blood test for prostate cancer.
Colorectal cancer is a leading cause of cancer death in the United States, with nearly 150,000 new cases expected to be diagnosed this year.
Brooks said it is important to ask questions of the doctor performing a colonoscopy to learn about his skill level. He suggests asking about the doctor's polyp detection rate (most find lesions in 15 percent to 25 percent of patients); how often his scope gets all the way to the juncture of the colon and small intestine (most make it about 95 percent of the time); and how long it takes for the doctor to withdraw the scope from the colon (faster than six minutes may be too fast).
Many doctors take time entering the colon, he said, but colonoscopy is a two-way procedure: Abnormalities can also be found on the way out as the twists, turns and folds of the colon are examined from another angle.
"It does raise the importance of careful and meticulous colonoscopy ... not just rushing through it," Choti said.
stephanie.desmon@baltsun.com
About colonoscopies
What is a colonoscopy?
Colonoscopy is used to visually examine your colon and rectum for abnormalities. A long, flexible tube with a video camera at the tip is inserted into the rectum. During the procedure, the doctor can remove polyps.
Who should get a colonscopy?
Generally considered the procedure of choice for colon-cancer screening, a colonscopy is recommended if you are over 50 years old, have a family history of polyps or colon cancer or have symptoms.
Who actually gets a colonoscopy?
Doctors say colonoscopy is a major tool in preventing colon cancer but that not enough people get it done. In a recent survey, the percentage of adults who reported having had a colonoscopy or similar procedure in the previous 10 years increased from 45 percent in 2002 to 50 percent in 2004, and to 56 percent in 2006. [Sources: Mayo Clinic; National Institute of Diabetes and Digestive and Kidney Diseases; Centers for Disease Control and Prevention]
