The 70-year-old underwent a 12-hour operation and spent 17 days in intensive care, after being struck by severe abdominal pain in April. Bolsonaro, who was president from 2019 to 2022, has had recurring health problems since he was stabbed in the abdomen at an election rally in 2018.
Doctors have previously described his condition as stable.
Meanwhile, the trial is approaching where the former president is accused of attempting to initiate a coup. It will be the first, since Brazil became a democracy in 1985, where a former leader in the country is accused of trying to force their way to power.
Bolsonaro risks a long prison sentence.
He had hoped to be able to stand in next year's presidential election, despite being barred by the court from standing in elections until 2030.
Corrected: In an earlier version of the text, there was an incorrect formulation about Bolsonaro's possibility to stand in next year's presidential election.
