直肠子 (zhíchángzi) Straightforward Person
"直肠子 (zhíchángzi)" is the phrase for "Straightforward person." The character "直 (zhí)" means straight or upright and "肠子 (chángzi)" means intestine.
Example:
Gébì Zhāng dàmā zhēn shì gè zhíchángzi, yǒu shá jiù shuō shá.
隔壁张大妈真是个直肠子，有啥就说啥。
Aunt Zhang next door is a straightforward person, who always says whatever's on her mind.
I wanted to spend a muinte to thank you for this.