WASHINGTON -- President George W. Bush will have a routine colonoscopy on Saturday at his mountaintop retreat at Camp David, Md., White House spokesman Tony Snow said Friday.

Bush To Get Colonoscopy

Snow said the president will hand over presidential powers to Vice President Dick Cheney under Section III of the 25th Amendment to the U.S. Constitution while he is under anesthesia.

"Once enacted, the vice president will serve as acting president until such time as the president notifies the appropriate authorities that he is prepared to reassume the authority of the president," Snow said. "The exact time and duration will be determined by the findings of the exam, but it's expected to be similar to that in 2002."

Snow said the transfer of power in 2002 was about 2½ hours.

The last time Bush had colon and rectal cancer surveillance was in June 2002. Doctors then advised him to have another colonoscopy in five years.

Snow said the president has had no symptoms.

Snow said Bush had polyps discovered and removed during routine screening exams prior to becoming president.

"Although no polyps were noted in the exam in 2002, age and history would suggest that there's a reasonable chance that polyps will be noted this time," Snow said. "If so, they'll be removed and evaluated microscopically."

Snow, who is currently undergoing chemotherapy for colon cancer, said his situation did not influence Bush's decision.