doc_text: Retired Sen. John Tower, the defense secretary-designate, underwent surgery Thursday to remove a colon polyp, a hospital spokesman said.
  "Senator Tower is resting comfortably and is listed in fair condition," hospital spokesman Steve Habgood said Thursday night.
  "The senator is expected to make a full recovery."
  Tower, 63, a U.S. senator from Texas for 24 years, was admitted to Baylor University Medical Center on Wednesday after undergoing a colonscopy examination last week that revealed the polyp, Habgood said.
  A preliminary biopsy of the polyp showed it was benign, Habgood said, but further results would be announced Friday by Tower's surgeon, Dr. R.D. Dignan, of Dallas.
  Thursday's surgery took approximately three hours, Habgood said.
  When Tower underwent the colonscopy examination, a rectal polyp also was discovered and removed.
  Tests of that growth showed it to contain some "malignant but well differentiated cells," Habgood said.
  Further explanation of the first polyp removal would have to come from Tower's surgeon, who was unavailable for comment Thursday night, the spokesman said.
  After leaving the Senate in 1985, Tower went into business as a defense consultant.
  He also served as an arms negotiator for President Reagan and he headed the White House's Iran-Contra investigative panel.
  President-elect Bush designated Tower as his defense secretary on Dec. 16.
  The nomination is subject to Senate approval.
summary_text: Former Senator John Tower, President Bush's nominee as defense secretary under went surgery to remove a colon polyp on Thursday.
  Senator Tower was listed in fair condition following the surgery and is expected to make a full recovery.
  Tower entered the hospital on Wednesday after a colonoscopy revealed the polyp.
  A preliminary biopsy of the polyp, which was removed during a three hour surgery, showed it to be benign.
  A rectal polyp was removed during the colonoscopy which showed malignant but well differentiated cells.
  An announcement on the first polyp was to come from Tower's surgeon on Thursday.