I was a health inspector. I inspected septic systems. I have used the terms in a professional setting for years. Sewage, Efluent (liquid from the tank), septage(everything in the tank), and*hi*. are the common terms. I'm fron NJ - I use the S-word most of the time. It is only through the mental filter of the keyboard that I refrain from writing it. Poop is easier to type than feces. Two letters, right next to eachother on the keyboard, get over it.
Plus, I have kids - poop is the word I use around my girls, now that I'm in the South. In NJ, it was ca-ca, ca-cas, or cockies.
I prefer turds, myself, when describing the solid, well-formed fecal bolus after exitign the digestive system. It describes so much in one syllable. Feces can mean anything from a firm, well-formed stool, to watery diareeah form a girardia patient. The S-word is even more vague. Poop is slightly more concise than the S-word, but still vague in it's actual constitution. Poop and the S-word are alaso verbs, which adds to their utility, but detracts from their specificity.
Turds, however, are simply turds. It may (S-word/poop) a mushy, watery mess of (S-word/poop) indicicative of innumerable parasitic nightmares. But, if your chameleon leaves turds on the floor, chances are all is well.