YOU SAID:
I pooped my pants yesterday
INTO JAPANESE
昨日ズボンをうんちした
BACK INTO ENGLISH
Pooped pants yesterday
INTO JAPANESE
昨日うんちパンツ
BACK INTO ENGLISH
Poop pants yesterday
INTO JAPANESE
昨日うんちパンツ
BACK INTO ENGLISH
Poop pants yesterday
That didn't even make that much sense in English.