Ulcer Cited as Latest Yeltsin Ailment

President Boris N. Yeltsin, whose poor health has left Russia without strong leadership for more than two years, was hospitalized again Sunday with what the Kremlin said was a bleeding stomach ulcer.

The Kremlin said Yeltsin, 67, would be confined to bed for an indefinite period but was in stable condition and would not transfer any of his constitutional powers to Prime Minister Yevgeny M. Primakov.

“The president feels fine,” Primakov told the Itar-Tass news service. “No extraordinary situation has arisen in the country due to the president’s illness.”

Presidential spokesman Dmitri D. Yakushkin said in a television interview that the ulcer could be the result of stress and might require surgery. But the president was upbeat, he said, despite having landed in the same hospital where he had quintuple bypass heart surgery in the fall of 1996.

“The president is rather cheerful, his voice is cheerful, and he aims to overcome the ailment and return to work as soon as possible,” Yakushkin said after talking with Yeltsin by phone.

With the country’s financial collapse in August and the inability of its economy to recover, Yeltsin has come under increasing pressure to step down and permit an early presidential election.

Last week, Moscow Mayor Yuri M. Luzhkov, the front-runner to succeed Yeltsin, criticized the president for not carrying out his duties. “Russia, as a presidential republic, should have an active president,” the mayor said.

Yeltsin has not been seen in public or visited the Kremlin since before New Year’s Day, but earlier he insisted that he will serve out his term, which ends in mid-2000. On Saturday, the Kremlin released a 20-second videotape without sound that showed Yeltsin meeting with his interior minister.

Yeltsin’s health has not been the same since he had a heart attack shortly before he won reelection in the summer of 1996. In addition to the bypass surgery, he has suffered numerous ailments, including two bouts of pneumonia.

During his rare public appearances recently, the president has at times seemed disoriented, laboriously signing official documents and pausing at length before answering questions. At other times, he has appeared to recover, speaking coherently and looking more vigorous.

Last fall, Yeltsin was forced to stop traveling abroad after he stumbled and nearly fell during a trip to Central Asia. The Kremlin said he suffered from the vague condition of “neuro-psychological asthenia,” which could range from exhaustion to dementia.

At the time, officials said that Yeltsin had turned over day-to-day management of the country to Primakov, who under the Russian Constitution would take over as acting president if Yeltsin died or became incapacitated.

Last month, Yeltsin’s health had improved to the point that he planned to resume his foreign travel. He is scheduled to go to Paris next week to meet with French President Jacques Chirac, but that trip would now seem unlikely.

One doctor who did not examine the president said a bleeding ulcer could pose a danger for a patient in Yeltsin’s condition. If the president suffers a significant loss of blood, that could impair the functioning of his already weakened heart. If medication does not stop the bleeding, surgery could be necessary.

“We don’t know how massive the hemorrhage is and how much blood the president has lost,” said Ilya M. Buriyev, a Moscow gastroenterologist and surgeon.