How we cite our quotes:
[Billy] was under doctor's orders to take a nap every day. The doctor hoped that this would relieve a complaint that Billy had: Every so often, for no apparent reason, Billy Pilgrim would find himself weeping. Nobody had ever caught Billy doing it. Only the doctor knew. It was an extremely quiet thing Billy did, and not very moist. (3.15.1)
The reason for Billy's weeping may not be apparent to the doctor, but is it apparent to us? Beyond Billy's war experiences, what else might he have to cry about?
And now there was an acrimonious madrigal, with parts sung in all quarters of the car. Nearly everybody, seemingly, had an atrocity story of something Billy Pilgrim had done to him in his sleep. Everybody told Billy Pilgrim to keep the hell away. (4.9.16)
An "acrimonious madrigal" in this context is a loud, furious, multipart harmony of people yelling at Billy. No one in the POW train car wants to sleep next to Billy because he whimpers and kicks so badly in his sleep. Why does no one ever show any sympathy for Billy's suffering? How do you respond to Billy's extreme portrayal as helpless and childlike? How might this portrayal fit into other themes such as fate and free will or men and masculinity?
Billy looked inside the latrine. The wailing was coming from in there. The place was crammed with Americans who had taken their pants down. The welcome feast had made them as sick as volcanoes. The buckets were full or had been kicked over.
An American near Billy wailed that he had excreted everything but his brains. Moments later he said, "There they go, there they go." He meant his brains. (5.53-6-7)
War stories often contain descriptions of wounds, but this book has little time for wartime casualties. We do, however, get a lot of illness: Weary's gangrene, Wild Bob's fever, and the soldiers' diarrhea here, to name a few. This focus on the suffering of the sick human body really underlines the physical exhaustion and depravation these POWs must cope with throughout the novel. Also, by focusing on diarrhea instead of, say, a bullet wound, Vonnegut is once again drawing the reader's mind away from any kind of battlefield heroism.