During the daily press briefing, Snow, a colon cancer survivor, said because Bush had more than three such polyps, he will next have to undergo another routine colonoscopy in three years. The president's last previous colonoscopy had been five years ago.

Bush's polyps -- called tubular adenoma -- were small, about 1 centimeter in size.

"They represent the various -- very earliest cellular changes," Snow said. "Left untreated, they can progress to larger, more advanced lesions and a small percentage could become cancerous."