Suharto, 86, was suffering from anemia, a dangerously low heart rate and swollen internal organs when he was admitted to Pertamina Hospital in critical condition Friday. He responded well to a blood transfusion and dialysis treatment, but his condition has again deteriorated, Dr. Subiandono told a news conference.
"We are looking for the cause of the bleeding," said Subiandono, adding that Suharto's red blood cell level had dropped. "He is worse than yesterday ... he will need to remain in intensive care so he can be closely monitored."
Subiandono said excess liquid in the lungs could lead to respiratory problems.
Doctors said earlier that Suharto would need a second pacemaker but his condition was not stable enough to perform the procedure.
Suharto, whose regime was widely regarded as one of most corrupt and brutal of the 20th century, was ousted after 32 years in power amid student protests and nationwide riots in 1998. But poor health has kept him from facing trial and supporters have repeatedly called for charges to be dropped.
Suharto, who, like many Indonesians goes by just one name, has received a steady stream of visits by high-profile officials at the hospital in recent days, including President Susilo Bambang Yudhoyono, Vice President Jusuf Kalla and Cabinet ministers and Muslim clerics.
"For the time being, he can receive no more visitors," Subiandono said.