The president had an intestinal obstruction and is in stable condition, a hospital in Sao Paulo said in a statement.
Brazilian President Jair Bolsonaro has been hospitalised with an intestinal blockage but is in stable condition.
The Vila Nova Star hospital in Sao Paulo said in a note that Bolsonaro was admitted there in the early hours of Monday due to intestinal obstruction.
"He is in stable condition, undergoing treatment and will be re-evaluated this morning by Doctor Antonio Luiz de Vasconcellos Macedo's team," the note said.
"At the moment, there is no forecast for him being discharged," it added.
A government statement published by the Globo media outlet indicated that Bolsonaro is “doing well” and further information will be provided later in a medical bulletin.
Earlier, TV network Globo showed images of Bolsonaro walking down the stairs of the presidential plane after landing in Sao Paulo at about 1:30 am local time (0430 GMT) and being immediately taken to Hospital Vila Nova Star.
The media outlet quoted Bolsonaro’s doctor Macedo as saying the president had stomach pains.
Globo said that Macedo was on holiday in the Bahamas and was waiting for a flight back to Brazil to see Bolsonaro, who reportedly had no public appearances scheduled on Monday.
The doctor also told news site UOL that the president would undergo several tests to examine his abdomen.
In July 2021, he was taken to the same hospital due to an intestinal blockage after suffering from chronic hiccups.
Since a knife attack that targeted him during a 2018 election campaign, in which he was stabbed in the stomach, Bolsonaro has undergone abdominal surgery at least four times.