HOUSTON (AP) _ Former first lady Barbara Bush underwent surgery on Wednesday, but hospital officials refused to comment on her condition or the type of operation.

``At her family's request, Barbara Bush is a no-information patient,'' Methodist Hospital spokeswoman Gina Johnson told Houston TV station KRIV.

Former President George Bush made reference to the surgery on Wednesday during an Indiana fund-raiser for his son, Gov. George W. Bush, a possible presidential candidate. Bush told a crowd in Indianapolis that his wife would be released from the hospital on Thursday.

There was no answer at the former president's Houston office on Wednesday night.