'retrocolonic' originates from the Latin prefix 'retro-' meaning 'back' and from 'colonic', ultimately from Greek 'kolon' via Latin 'colon', meaning the large intestine or 'colon'.

'retrocolonic' is a modern medical formation (Neo-Latin/English) combining 'retro-' + 'colonic' to denote position behind the colon; it developed by straightforward compoundation in medical usage.

The components originally meant 'back' (retro-) and 'colon' (kolon); combined, they came to mean 'situated behind the colon' in anatomical contexts.