衷 ('inner; from the heart') +
肠 ('intestines'). Chinese pictures deep emotion as residing in the gut, not just the heart - hence the literal 'inner-intestines' for 'heartfelt feelings'. Lives almost exclusively in fixed phrases:
倾诉衷肠 ('pour out one's heart'),
共叙衷肠 ('share innermost feelings together'),
互诉衷肠 ('mutually confide').
