
The rate of undiagnosed colorectal cancers in patients undergoing colonoscopy is influenced both by where the screening procedure takes place and by who is performing the exam.
A colonoscopy involves the insertion of a lighted tube with a small camera into the bowel. It is used to visually detect colorectal cancer and precancerous polyps.
Cancers are more likely to be missed when the colonoscopy is performed in an office setting, and also more likely to go unnoticed when the procedure is conducted by an internist or family physician rather than a specialist.
An office procedure, as opposed to one conducted in a hospital setting, tripled the risk of missed colorectal cancers in men and doubled the risk in women. Family physicians and internists were 77 percent more likely than gastroenterologists to miss the cancer in men and 85 percent more likely to miss it in women.