noun
diarrhea; the runs
Colloquial and somewhat childish or jocular term for diarrhea. Often used in casual conversation or online. The ピー is onomatopoeic, mimicking the sound of loose stool.
昨日食べたものが悪かったのか、朝から下痢ピーが止まらない。
Maybe it was something I ate yesterday, but I've had the runs since this morning.
お腹が痛くて、下痢ピーになりそう。
My stomach hurts and I feel like I'm going to have diarrhea.
Compound of 下痢 (geri, 'diarrhea') and the onomatopoeic slang suffix ピー (pī), imitating the sound of loose stool. The exact origin of the suffix is uncertain, but it is common in colloquial and childish language.