Extensive cleansing of the bowel is not necessary for patients undergoing virtual colonoscopy, Dutch researchers report in the journal Radiology.

Virtual colonoscopy, also known as CT colonography, involves the use of CT to create images that are analyzed by software to create a 3-D picture of the colon, similar to what is seen when conventional colonoscopy is used. By avoiding the discomfort of regular colonoscopy, researchers are hopeful that virtual colonoscopy will result in more and more people being screened for colon cancer.

Dr. Sebastiaan Jensch of the University of Amsterdam and colleagues note that limited preparation might improve patient compliance with screening. Patients, they add, find cathartic bowel preparation the most difficult part of the procedure.

A technique called fecal tagging allows any fecal material to be distinguished from polyps or cancer, so no extensive bowel cleansing is necessary. Jensch told Reuters Health that with reduced cleaning, “the overall burden of the preparation was perceived by 74 percent of patients as none or mild.”

To confirm the accuracy of the limited cleaning approach, the researchers studied 168 patients at increased risk for colon cancer who underwent CT colonography after fecal tagging. They also underwent standard colonoscopy.

Overall, 114 patients had polyps, of which 56 were 6 millimeters or larger and 17 were 10 millimeters or larger.

CT colonography detected 76 percent of polyps 6 millimeters or larger and 82 percent of polyps 10 millimeters or larger.

Detection rates were higher for regular colonoscopy, at 91 percent for polyps 6 millimeters or larger and 88 percent of those 10 millimeters or larger, but the difference was not significant from a statistical standpoint.

SOURCE: Radiology, April 2008.