Surgeons managed to stabilize the comatose Israeli prime minister after initially fearing for his life, but the latest complication makes it even more unlikely he will recover.
Israelis closely followed their 77-year-old leader's latest ordeal, with TV stations repeatedly breaking into regular programming for updates, but the country already has come to terms with his departure from politics.
Sharon's political heir, Ehud Olmert, quickly took the reins as acting prime minister after Sharon's Jan. 4 stroke and appears poised to lead Sharon's centrist Kadima Party to victory in March 28 elections.
Sharon was rushed to surgery Saturday morning after doctors, who had noticed abdominal swelling, conducted a CT scan and a laparoscopy, or insertion of a small camera through the abdominal wall.
Surgeons detected necrotic — or dead — tissue in the bowels and removed 20 inches of his large intestine, Hadassah Hospital director Dr. Shlomo Mor-Yosef said.
The necrosis was caused either by infection or a drop in the blood supply to the intestines, something common in comatose patients, the hospital director said. Mor-Yosef said doctors did not find blocked blood vessels.
Mor-Yosef said Saturday's surgery was relatively simple, and that Sharon's main medical problem continues to be the coma. Asked whether Sharon could come out of the coma, Mor-Yosef said: "All possibilities remain open, but with each passing day, the chances are lower."
Since the stroke, Sharon has been hooked up to feeding and breathing tubes.
President Bush was being kept informed of Sharon's condition by his staff, White House spokesman Scott McClellan said Saturday.
"Prime Minister Sharon remains in our thoughts and prayers during this difficult time," McClellan said.
Dr. R. Sean Morrison, a professor of geriatrics at the Mount Sinai School of Medicine in New York, said "long-term comatose patients typically die of complications like this," referring to necrosis.
Morrison said Sharon's prognosis was grave even before the latest complication, and his chances for survival are now "extremely small, almost zero."
In recent months, the obese Sharon had repeatedly brushed aside questions about his health, but his condition became an issue after he suffered a mild stroke Dec. 18.
At the time, Sharon was at the height of his popularity, following last summer's successful pullout from the Gaza Strip and his break with the hard-line Likud Party.
Voters widely expected Sharon to draw Israel's final borders, with or without the Palestinians, if elected for a third term. Polls suggested Kadima would become by far the largest party in parliament.
Sharon, a war hero, had for years opposed concessions to the Palestinians. He came to accept the idea of giving land to the Palestinians and allowing them to form a state only during his most recent term as prime minister, which began in 2003.
After his mild stroke, aides played down his health problems. Doctors treated him with anti-clotting agents and scheduled a minor heart procedure for Jan. 5 to close a hole believed to have contributed to that first stroke.
Hours before the scheduled procedure, Sharon suffered a massive stroke, including heavy bleeding in the brain, and slipped into a coma.
After being admitted to Hadassah on Jan. 4, Sharon underwent three back-to-back brain surgeries. These were followed by three smaller procedures, including insertions of feeding and breathing tubes — a sign that doctors were preparing for a long-term coma. Throughout the past five weeks, he had been in critical but stable condition.
Before dawn Saturday, Sharon's condition deteriorated sharply and his life was in danger, hospital officials said. Doctors decided to operate after consulting with Sharon's sons, Omri and Gilad, Mor-Yosef said.
Experts have concluded that Sharon apparently suffered severe brain damage and is unlikely to regain consciousness. If he does awaken, most say, the chances of his regaining meaningful cognition or activity are slim.
Sharon's stroke had jolted Israel, but the transition period has been surprisingly smooth.
Kadima has held steady in the polls, which predict the party will win at least 40 of the 120 seats in parliament. This means Olmert would form the next government, likely in a coalition with the dovish Labor Party.
In a TV interview earlier this week, his first since taking over, Olmert suggested he would withdraw from large areas of the West Bank if elected, but he did not make clear whether he would act unilaterally. Olmert said Israel will give up the parts of the West Bank where most of the Palestinians live but retain the main Jewish settlement blocs.
The Palestinians claim all of the West Bank as part of a future independent state.
Unilateral action appears increasingly likely in light of the victory of the Islamic militant group Hamas in last month's Palestinian parliamentary elections. Olmert has said Israel will shun a Hamas government unless the group — considered a terrorist organization by the United States and Europe — renounces violence and recognizes Israel.
Hamas has killed hundreds of Israelis in attacks.