A minimally invasive cancer-screening technique known as capsule endoscopy, also known as the "camera pill" appears to be less effective than standard colonoscopy at identifying precancerous polyps and cancer, new research from Belgium suggests.

In capsule endoscopy a patient swallows a tiny, battery-operated, excretable capsule fitted with a double-sided video camera to look at the colon. Experts agree that capsule endoscopy -- which does not require sedation -- is indeed a safe and less invasive technique for visualizing the colon.

The study involved more than 300 patients who were scheduled to undergo a colonoscopy at one of eight medical centers, because they either had a history of colon cancer or were suspected of having the disease. The patients underwent capsule endoscopy and, after that, conventional colonoscopy.

The pill procedure detected only 64 percent of polyps 6 millimeters in size or larger that were identified by standard colonoscopy. And with similarly sized advanced cancer, capsule screening captured just 73 percent of tumors that were spotted by colonoscopy. Of 19 confirmed cases of colon cancer uncovered through colonoscopies, just 14 were found by the pill technique, the researchers noted.

The scientists concluded that capsule endoscopy is currently inferior to colonoscopy as a screening method, but they called for more research. They say the noninvasive technique of the camera pill has the potential to encourage more patients to get screened for colon cancer.