搜索枯腸 [－－－肠]

Jyutping sau2 saak3 fu1 coeng4
Pinyin sōu suǒ kū cháng

Definitions (CC-CEDICT)
  1. to rack one's brains (for apt wording etc) (idiom)
Definitions (Wiktionary)
  1. phrase, idiomatic
    to rack one's brain; to think extremely hard