There's a fair bit of defecation in the Bible. Saul shitting in a cave, I forgot where, or Paul calling all material things 'skubala', i.e. waste, as in junk, poop, refuse, basically what we'd call shit today:

https://www.greekbible.com/philippians/3/8

Edit: This also seems like a decent opportunity to bring up the scatological Luther.

https://www.wilsonquarterly.com/quarterly/summer-2012-americ...

Also Ezekiel 4:9-13, where God commanded Ezekiel to bake bread in a fire fueled by human shit because He was angry at the Israelites, but Ezekiel haggled God down to just using cow shit.