Fidel Castro, who turns 80 on Sunday, issued a statement playing down speculation that he was seriously ill and his rule might be coming to an end.
An announcer on state-run television who said he had just spoken to Castro quoted the president as saying the Caribbean island was functioning well in his absence.
Castro did not appear on screen and there was no recording of his voice. He didn’t say when he might be able to resume his government duties.
"The important thing is that everything is working and will continue to work perfectly well in the country," he said. "I am in perfectly good spirits."
Castro passed power to his brother Raul, the country's defence minister, on Monday while he underwent the surgery.
"I am in perfectly good spirits."
Fidel Castro, Cuban president, after intestinal surgery
Raul, Castro's designated successor, assumed the posts of Communist Party head, armed forces' commander-in-chief and president of the Council of State.
National Assembly President Ricardo Alarcon sought to calm concern that Castro's death might be imminent.
"The Cuban leader will always fight until the last moment. But that last moment is very far away," he said.
Cuban exiles in the United States celebrated news of Castro's illness hoping that an end to 47 years of communist rule was near.