BOGOTA, Colombia — The leader of Colombia’s once-largest rebel group will undergo heart surgery after being hospitalized while campaigning for president.

Bogota’s Shaio Clinic issued a statement Friday saying it recommended the unspecified procedure after carrying out a battery of tests on Rodrigo Londono.

The rebel leader best known by his nom de guerre Timocehnko was hospitalized Thursday suffering from chest pain.

The 59-year-old Londono has suffered various health setbacks in recent years, including a heart attack in 2015 during peace talks in Cuba and a stroke last year.

The former rebels are transitioning to civilian life after reaching an historic peace accord to end Latin America’s longest-running conflict in 2016.

Timochenko’s bid for president has been rife with conflict, with angry Colombians throwing eggs at him on several occasions.