A spreading stain overshadowed the Colombian president's impassioned campaign speech Sunday.

Colombian President Juan Manuel Santos, elected in 2010, kicked off his reelection campaign with a speech to supporters in Barranquilla this weekend. But footage of the president apparently wetting himself onstage (starting around :10) is raising questions about the 62-year-old's health.

Santos, who appears to be unaware, was diagnosed with prostate cancer in 2012. He underwent surgery to remove a prostate tumor that same year, which his doctors said gave him a 97 percent chance of beating the disease. He has not publicly mentioned any health issues since.