Daijr, Koj

They all see to have the figurative sense, but give the Chinese medicinal meaning as the source.
I think this shorter form works.

@@ -12,2 +12,3 @@
-<gloss>licking excrement</gloss>
-<gloss g_type="fig">throwing away one's respectability and sense of shame in trying to win somebody's favor</gloss>
+<gloss>shamelessly flattering</gloss>
+<gloss>brown-nosing</gloss>
+<gloss g_type="lit">licking excrement</gloss>

daijs only lists the figurative sense but googling comes up 
with many (maybe dubious?) Japanese sources saying licking 
excrement is part of making a diagnosis in traditional 
medicine in China and/or Korea, so it seems the literal sense 
might be more common

daijs