Pope John Paul II is receiving supplementary nutrition through a feeding tube as he continues his “slow and progressive” recovery, the Vatican announced.

Papal spokesman Joaquin Navarro-Valls said March 30 that a nasogastric tube was inserted in order to improve the pope’s caloric intake and help him regain his strength.

The pope underwent a tracheotomy to relieve breathing problems in late February. He is also believed to have Parkinson’s disease, which often causes difficulty in swallowing.

The written announcement came just a few hours after the pope made a surprise appearance at his studio window to bless thousands of pilgrims gathered below in St. Peter’s Square. The pope had also tried to speak to the crowd using a microphone, but the few syllables he uttered were incomprehensible.

“The Holy Father continues his slow and progressive convalescence,” Navarro-Valls said in a written statement.

“The pope spends many hours of the day in an armchair, celebrates Mass in his private chapel and stays in working contact with his collaborators, directly following the activity of the Holy See and the life of the church,” Navarro-Valls wrote.

But he said that in order to boost his caloric intake the pope was being fed through a nasogastric tube, or a narrow, flexible tube that goes through the nose down into the stomach, through which liquid food and water can be administered.

“In order to improve caloric intake and to favor the regaining of strength, enteral nutrition has begun through the placement of a nasogastric feeding tube,” the statement said.

Navarro-Valls said the pope’s medical care continued to be provided by his personal doctor, Renato Buzzonetti.

A Vatican official said the feeding tube was being used to offer additional nutrition. He said the pope could continue eating and drinking.

The tube was inserted just after the pope’s public appearance at his studio window March 30, said the official.

Dr. Gianfranco Cappello, a professor on the surgery faculty at Rome’s La Sapienza University and a specialist in tube feeding at the nutritional clinic at Rome’s Umberto I hospital, said if he were Pope John Paul’s doctor, he would have begun feeding the pope through a nasogastric tube weeks ago.

“I have 345 patients being nourished through nasogastric tubes, and many of them have Parkinson’s disease,” he said. “When they become dysphagic (have difficulty swallowing), anything they ingest, but particularly fluids, tend to go down the wrong way and end up in their lungs.”

The presence of the tube, inserted through the nose, “is absolutely not bothersome,” the doctor said.

Cappello said a prepackaged nutritional formula is introduced into the tube several times a day, but the tube is usually not inserted and removed throughout the day.

“It would be mean to keep putting it in and taking it out,” he said.

The tube is thin, held in place with a small bandage and the patient can still talk and eat, “although it is best not to, since food still can go down the wrong way,” he said.

Cappello said that generally once one of his Parkinson’s patients begins being nourished with a nasogastric tube, it is the chief method of nutrition for the rest of the patient’s life.

“I have many patients who have been using the tube for years,” he said.

While the Vatican said all public audiences with the pope “continued to be suspended,” a Vatican official said “surprise appearances were always possible.”

The pope’s four-minute appearance shortly after 11 a.m. March 30 was a surprise to many people.

Looking alert and sitting erect, the pope attempted to speak to the crowds below with a microphone, but the few syllables he uttered were incomprehensible. His personal assistant abruptly removed the microphone before the pope could finish.

The last time the pope attempted to speak to the public was on Easter, March 27. He was given a microphone and mouthed the words of the blessing, but the only sound heard was his deep, rasping breathing.

No papal appearance or general audience had been scheduled for March 30, but thousands of pilgrims flocked to the square anyway in the hopes the pontiff would make a surprise appearance at his fifth-floor apartment window to bless the crowds.

Thousands had been disappointed just two days earlier when Pope John Paul skipped a traditional noon blessing on Easter Monday.

But early March 30, a notice appeared on the four giant television screens in St. Peter’s Square, saying the pope would come to his studio window to bless the faithful.

The appearance turned into a very brief, almost impromptu, general audience.

“This was a huge surprise,” said Ignacio Hernandez from Salinas, Calif.

“I was told he was sick, but what a thrill to have seen him in his own home even,” he said.

Hernandez, who sat in a wheelchair in the square, said seeing the pope make such an effort to be with the people made him feel that “I can accomplish things. For me, this means a lot.”

The pope, who continued to exhibit uncontrolled facial expressions, vigorously blessed the thousands of people in the square while aides read out papal greetings in Italian, German and Polish.

An aide led the Our Father in Italian and recited the apostolic blessing in Latin while the pope again blessed the crowd.