盲腸　mouchou　appendix

大腸　daichou　large intestine

小腸　shouchou　small intestine

十二指腸　juuni-shichou　duodenum (literally ‘twelve finger intestine’)

断腸　danchou　heartbreak (or literally, severed intestines)

腸 can also be pronounced ‘harawata’, which, broken down into ‘hara’ and ‘wata’, means ‘stomach cotton’ (like a stuffed animal)

はらわたが煮えくり返る　harawata ga nie-kurikaeru　to be furious; to seethe with anger; to have one's blood [intestines] boiling

鉄心石腸　tesshinsekichou　will of iron (literally ‘iron heart stone intestines’)

鼓腸　kochou　flatulence

kanchou   and I quote from Wikipedia: “Kanchō (カンチョー) is a prank performed by clasping the hands together in the shape of an imaginary gun and attempting to poke an unsuspecting victim's anus, often while exclaiming "Kan-CHO!".[1] It is a common prank among children in East Asia such as Japan... The word is a slang adoption of the Japanese word for enema (浣腸 kanchō).[7] In accordance with widespread practice, the word is generally written in katakana when used in its slang sense, and in kanji when used for enemas in the medical sense.”

綿抜き　watanuki　gutting (esp. a fish); gutted fish

羊腸　youchou　1. winding; zigzag; meandering​  2. sheep intestines (​orig. meaning)

九回の腸　kyuukai no chou　having one's guts twisted in anguish; deep grief; heartbroken thoughts​

海鼠腸　konowata　salted entrails of a sea cucumber; salted entrails of a trepang