There is reason in his madness.
We do go on about toilets on TreeHugger, and just recently offended many in Scotland by complaining about their bathrooms. So I am envious of the Dear Leader from North Korea, who traveled to his summit with the Dear Leader from the USA with his own private toilet. According to the Chosunilbo, a South Korean newspaper, it was sent ahead.
First to arrive in Singapore was an IL-76 transport plane carrying food and other essentials for Kim as well as his bullet-proof limousine and a portable toilet that will deny determined sewer divers insights into to the supreme leader's stools.
According to the Washington Post, this is important and highly secure poop.
“Rather than using a public restroom, the leader of North Korea has a personal toilet that follows him around when he travels,” said Lee Yun-keol, who worked in a North Korean Guard Command unit before coming to South Korea in 2005. “The leader’s excretions contain information about his health status so they can’t be left behind,” Lee said.
According to Christina Capatides of CBS News, this is standard practice.
"The restrooms are not only in Kim Jong Un's personal train but whatever small or midsize cars he is traveling with and even in special vehicles that are designed for mountainous terrain or snow," a source in South Pyongan Province familiar with Kim's Escort Command told the DailyNK in 2015. "There are multiple vehicles within the convoy so that people cannot tell which one he is in, and there is a separate car that acts as his restroom."
She then ends her story with a Pulitzer of a pun.
So, in this respect at least, it seems this historic summit is no different than Kim's other excursions. He simply always uses a personal, highly guarded toilet in "loo" of public facilities.
Evidently, there is a real history of peeping at political poop; according to the New York Post, the CIA and Britain's MI6 tried to check out Mikhail Gorbachev's leavings.
Joseph Stalin was also said to have spied on Mao Zedong, the Chinese communist who founded the People’s Republic of China party, by collecting his caca in 1949 and carefully examining it in a secret laboratory, BBC News reported.
So it probably makes sense for Kim to pack it out.