One such case is in Philipians 3:8, wherein Paul is claiming that in contrast to the value of knowing Christ Jesus, all other things are "rubbish".
This word "rubbish" (skuvbalon) seems to be a sanitized version of what the actual word means. Here's a summary from Daniel B. Wallace:
That skuvbalon took on the nuance of a vulgar expression with emotive connotations (thus, roughly equivalent to the English “crap, s**t”) is probable in light of the following considerations: (1) its paucity of usage in Greek literature (“Only with hesitation does literature seem to have adopted it from popular speech” says Lang in TDNT 7:445); (2) it is used frequently in emotionally charged contexts (as are its verbal cognates) in which the author wishes to invoke revulsion in his audience; (3) there is evidence that there were other, more common and more acceptable terms referring to the same thing (in particular, the agricultural term koprov and the medical term perivsswma); (4) diachronically, the shock value of the term seems to have worn off through the centuries; and (5) a natural transfer of the literal to a metaphorical usage, in which disgust, revulsion, or worthlessness are still in view, argues for this meaning as well. Nevertheless, that its shock value was not fully what “s**t” would be is suggested in the fact that in the Hellenistic period (c. 330 BCE-330 CE) the word was also used on occasion for “gleanings” or “table scraps.”In other words, it appears that the word which God inspired is somewhere between "crap" and "sh*t".
(From http://bible.org/article/brief-word-study-skuvbalon - Go read the entire article for a fuller treatment)
Offends our sensibilities, doesn't it? But if it's true (and it seems to be), it is what it is.