YOU ASKED, WE ANSWERED: Answers to Viewers' Pressing Colon Questions

March 6, 2008— -- Dr. Robert Smith is the director of screening for the American Cancer Society and co-author of a new report on colonoscopy and colon cancer screening.

Below are his answers to your questions about colonoscopy.

Pat from Ocean, N.J., asked: "I was told last week after my second colonoscopy in five months that I had a flat polyp, which the doctor could not remove. She said I would need another procedure. How is a flat polyp removed?"

Smith: There are several methods for removing flat polyps. One method, known as endoscopic mucosal resection (EMR), involves inserting a needle next to the polyp and injecting saline to raise it above the wall of the colon, after which a special snare is used to remove it. If the lesion does not rise, it can be biopsied. Surgery also is an option.

Pam from Tucson, Ariz., asked: "How long should it take for the doctor to examine me for both flat and depressed lesions, and polyps, aside from the prep. time?"

Smith: There is no single answer to this question, but the exam times for both the flat and raised polyps average about 35 minutes. For some individuals, the exam will take longer, and for others it can take less time.

Anita from Clarksville, Tenn., asked: "I had a colonosocopy this year with the removal of one polyp. But the doctor couldn't complete the test, because he said that that my colon was 'twisted' and he sent me to the hospital for a barium enema. How reliable is the barium enema?"

Smith: The barium enema has good accuracy for polyps or cancers 1cm in size or larger, which are the abnormalities in the colon we're most concerned about.

Linda from Hasbrouck Heights, N.J., asked: "I recently had a colonoscopy done and the doctor determined that my colon is twisted due to prior surgery, and she could not complete the procedure. She recommended an upper GI, which I also did and the test results were OK. Although there is no history of colon cancer in my family, do you feel that I have done enough to have sufficiently checked out my colon?"

Smith: Guidelines recommend that an incomplete exam should be followed up with another option that can complete the exam. In this case, either a CT of the colon or a barium enema would be advised.