saliva	唾液
spit	唾沫

to salivate	分泌唾液
to spit - spat	吐痰

My stomach is grumbling. I'm hungry!

我的肚子在咕咕叫。我饿了！

Please don't spit on the sidewalk.

请不要在人行道上吐痰。

to burp	打嗝
to belch	打嗝
to hiccup	打嗝

to have the hiccups

打嗝

intestines	肠子
bowels	肠子
guts	内脏
indigestion	消化不良
nauseous	恶心
heartburn	胃灼热

to digest	消化
to feel queasy	感到恶心

to vomit	呕吐
to throw up - threw up

I'm feeling sick. I think I'm going to throw up.

constipation	便秘
diarrhea	腹泻
bowel movement	排便
gas	气体
fart	屁

to fart	放屁
to pass gas	排气

feces	粪便
excrement	排泄物
crap	大便

to defecate

排便