In today's daf yomi, Berachot 62b:
רַבִּי אֶלְעָזָר עָל לְבֵית הַכִּסֵּא. אֲתָא הַהוּא רוֹמָאָה דַּחֲקֵיהּ. קָם רַבִּי אֶלְעָזָר וּנְפַק. אֲתָא דְּרָקֹונָא שַׁמְטֵיהּ לְכַרְכְּשֵׁיהּ. קָרֵי עֲלֵיהּ רַבִּי אֶלְעָזָר: ״וְאֶתֵּן אָדָם תַּחְתֶּיךָ״, אַל תִּקְרֵי ״אָדָם״ אֶלָּא ״אֱדוֹם״.
The Gemara relates that Rabbi Elazar entered a bathroom. This Roman came and pushed him away. Rabbi Elazar stood and left, and a serpent came and ripped out the intestines of the Roman. Rabbi Elazar recited the following verse about the Roman: “Therefore I will give man [adam] for you” (Isaiah 43:4); do not read it as adam, but rather read it as Edom, meaning a Roman.
Rashi translates כַרְכְּשֵׁיהּ as חלחולת שהרעי יוצא בו שקורין טבחיא, and so Artscroll translates it as rectum. (Rect 'um? Dang near killed 'im!)
I think the derasha here is more than the al tikrei for Adam / Edom. It is also based on the word tachtecha. Therefore I will give an Edomite as for your rectum.
Assuming the Babylonian Amoraim were Ashkenazim, there could be a similar derasha at play in the segment that follows, on the pasuk: ״וְאָמַר לַהֲרָגֲךָ וַתָּחָס עָלֶיךָ״, about what happened when King Shaul went to relieve himself.
