Not necessarily, and not even the authors of the studies claim that colonoscopy should replace sigmoidoscopy as the recommended screening test. But their results offer support for that position. We're not talking about investigating an individual with symptoms suggestive of disease. You take laxatives the night before and an enema or two on the morning of the exam. The procedure takes five to 15 minutes, and you hop off the table fit for work, tango lessons or shopping.
Colonoscopy is a different beast altogether.
At the gastroenterologist's office, you are mercifully given intravenous sedation for the procedure, which may take 30 to 45 minutes. Afterward, you lie around awhile, then someone has to take you home, where you are not fit for much of anything more demanding than dozing in front of the TV for the rest of the day. And so you've occupied yourself for a full 24 hours preparing for, and recovering from, colonoscopy. And you've had to enlist someone to take you home and put you to bed. Costs vary according to who is charging and who is paying, but it runs five to 10 times more than flexible sigmoidoscopy.