A book by Quan Yanchi who got those intimate details from Mao’s former body guard Li Yinqiao.
page 45: [..Mao toured Shanghai in 1958.. and went to watch The Story of the White Snake.]
The row was made up of single soft chairs in cloth covers. I sat next to Mao so as to be close to him, as was required of a guard on 24-hour duty. Mao was big-bellied; when he sat down I loosened his waist-belt as usual so that it wouldn’t become to [sic too] tight for comfort.
.. His nostrils began to twitch, and tears moistened his eyes. Soon, the tears began to cascade down his cheeks in large drops and splash onto his chest.
And then something quite unexpected happened.
In a sudden outburst of anger, Mao, slamming his big hand down on the armrest of the chair, shot up from his seat, proclaiming, “Revolution! Rebellion! Th’s the only answer!”
I was totally unprepared for anything like that. With his waist-belt loosened, his pants dropped the moment he stood up. As if propelled by a ramrod, I dashed to him, got hold of his pants and pulled them up. ..
What plagues Mao
Two things troubled Mao almost all his life: bowel movement and sleep.
It was a quiet night. The rain had made the fields soggy. Mao stopped at a small mount and loosened his belt. When I knew he was going to relieve himself, I relaxed a bit.
Mao squatted down. I kept a watch round-about. concealing myself in the darkness. I don’t recall how long he remained in that position. When he rose at last, he didn’t walk away immediately; squatting down too long must have numbed his legs, and when he moved away his steps were unsteady.
“Why didn’t you use the toilet, Comrade Chairman?” I asked.
“It stinks. The smell there hurts your brain,” Mao grumbled.
.. Then he asked me, “Shall we reach another agreement? Every time I want to relieve myself, you grab a shovel and dig a hole for me. What do you say?”
“Agreed,” I said. That’s what I did from then on, even after Mao moved to Zhongnanhai in Beijing: I would dig a hole and fill it up again. It was only after Zhou Enlai had a toilet designed and built especially for Mao, in his bedroom, that I was relieved of the shovel duty.