ROME -- Pope John Paul II, victim of intestinal ailments at the beginning of the week, has resumed normal activities and was to celebrate a mass on Saturday for his two predecessors and meet the president of the Philippines as he began a demanding autumn schedule.

The mass in honor of popes John Paul I and Paul VI was to be the pontiff's first appearance since, in a rare move, he was forced to cancel his weekly audience because of ill health attracting heavy media attention.

Television images of the 83-year-old pope looking pale, exhausted and dribbling slightly as he instead delivered his weekly blessing by radio on Wednesday touched off a wave of concern about his health.

John Paul suffers from the impact of a 1981 assassination attempt, Parkinsons disease and crippling hip and knee problems that keep Vatican technicians busy thinking up new ways of keeping him mobile. On his first full day back in his Vatican apartment Friday following a three-month summer vacation in the hills outside Rome, the pope met a group of Philippine bishops in preparation for an audience with President Gloria Arroyo on Saturday morning.

Despite persistent rumors he might resign, the pope's schedule is busy for weeks ahead.

Vatican reports said he would on Sunday summon a meeting of cardinals known as a consistory, at which new members would be admitted into the scarlet-robed college.

By appointing senior churchmen faithful to his views, the pope would be able to influence the election of his successor.

Vatican sources said the consistory was likely to coincide with the presence in Rome of the world's cardinals for the 25th anniversary of the pope's election on October 16.

Before then, the pope was scheduled to travel October 7 to a Marian shrine at Pompei. Vatican engineers have devised a special lift that will enable him to board and descend from a helicopter during the half-day trip.

While ailing, the pope has adamantly insisted that he will not step down because of ill health or age, although church law would permit him to do so if he were incapable of running the Catholic church.