Brazilian President Jair Bolsonaro has said his doctors are evaluating a potential surgery in his intestine, adding he is using a nasogastric tube.
The far-right leader was rushed to hospital early this morning, local media reported.
In a post on Twitter, Mr Bolsonaro said he started to fell unwell after lunch yesterday and was hospitalised in Sao Paulo at 3am
He has required hospital treatment several times since he was stabbed during his presidential campaign in 2018.
Mr Bolsonaro, 66, who has been in power since 2019, is being treated at Vila Nova Star hospital in Sao Paulo.
TV Globo showed images of him disembarking from the presidential plane on foot with his entourage.
Doctor Antonio Luiz Macedo, who has operated on President Bolsonaro on other occasions, told news site UOL that the president would undergo several tests to examine his abdomen.
In July, Mr Bolsonaro spent four days receiving treatment for an intestinal obstruction.
Since a knife attack that targeted him during a 2018 election campaign, in which he was stabbed in the stomach, he has undergone abdominal surgery at least four times.
About a month before he was elected president, Jair Bolsonaro was stabbed at a campaign rally by a man who was found to be psychologically unfit for trial.