hindgut

from WordNet (r) 3.0 (2006)

hindgut
    n 1: the caudal part of the alimentary canal in vertebrate
         embryos

from The Collaborative International Dictionary of English v.0.48

Hindgut \Hind"gut`\, n. [Hind, a. + gut.] (Anat.)
   The posterior part of the alimentary canal, including the
   rectum, and sometimes the large intestine also.
   [1913 Webster]