haveHave you thought about the words: Kot / Exkrement / Ausscheidung(en) or wich
Or which are rather funny: Köttel / Kacki (everything sounds cute / funny if uyou put an "i" behind it) / Brocken / Haufen (often used by some of my Friends "Ich hab einen riesen Brocken/Haufen gelegt").
I hope you find something useful.