Why North Korea has to hide Kim's poop

He’s staying in one of the world’s finest five star hotels, but Kim Jong Un still brought a toilet with him to Singapore. Kim does so because according to one North Korean military defector, the leader’s “excretions contain information about his health status so they can’t be left behind.”

Sorry, Kim, bringing your toilet to Singapore won’t prevent you from leaving behind biological material. Moreover, it’s a point of intelligence interest in and of itself why exactly the North Koreans are so concerned about Kim’s excrement. What does Kim have to hide?