ROME, Jan. 3 -- For the first time, a person in a position to know has acknowledged that Pope John Paul II is suffering from Parkinson's disease.

"The numerous operations he has undergone and the Parkinson's disease have caused him great suffering," said Gianfranco Fineschi, an orthopedic surgeon who operated on the pope in April 1994 when he broke his right leg in a fall in his apartment.

Tired and suffering the effects of several operations, the 80-year-old pope "should slow down and take a rest," Fineschi said in an interview with an Italian news magazine. Fineschi acknowledged that such an admonishment to the determined pontiff was probably "useless."

Excerpts from the interview in Oggi magazine, which will be on newsstands Thursday, were released today by the ANSA news agency. "Every time he leaves for a trip or he wears himself out during a public appearance, I fear for him," Fineschi was quoted as saying.

The pope's tremulous left hand, rigid facial expressions and shuffling gait have become increasingly noticeable over the past several years, leading outside medical experts to speculate that he had Parkinson's. Neither the Vatican nor, until now, his doctors had publicly confirmed the commonly held perception.

The closest the Vatican came such a statement came in October 1996, when papal spokesman Joaquin Navarro-Valls said John Paul's symptoms were the result of an "extrapyramidal syndrome," a term that applies to a group of neurological disorders including Parkinson's.

John Paul's stamina and courage have brought him additional respect and compassion as he has continued his travels and involvement in world affairs despite his physical difficulties.

The pontiff looked especially frail and tired at this year's Christmas ceremonies at the Vatican. He canceled a planned rest at the papal vacation residence in the Alban Hills south of Rome so he could give a quick wave and greeting daily from his window to the thousands of people who gathered in St. Peter's Square during the holidays.

Over the past year, special Jubilee events to mark the millennium added to the pope's official functions, Masses and audiences, an effort that has clearly strained him.

"The Holy Father has a powerfully muscular body, like that of a swimmer, but without the help of God he wouldn't have been able to maintain such activity," ANSA quoted Fineschi as saying.

Every time the pope misses a scheduled appearance, Italian newspapers are full of speculation about his health and longevity -- and possible successors.

Last January, Karl Lehmann, a prominent German bishop, suggested that the pope might consider retiring if he felt his health was impeding his role as leader of the world's 1 billion Roman Catholics. The Vatican vehemently denied the pope had any such intention.

Once a vigorous athlete who loved skiing, soccer and hiking, John Paul has had more than his share of physical trials. He was shot in the abdomen and left hand in an assassination attempt in St. Peter's Square in May 1981. In July 1992, he underwent surgery to remove a tumor from his intestine; in 1993, he dislocated his right shoulder; in 1994, he broke his leg; and, in 1996, he had an appendectomy.Outside medical experts have often speculated on the health of Pope John Paul II, 80, who has appeared increasingly frail.