Diarrhea, Diarrhoea
noun, verbal noun, の adjective
Diarrhea that goes below you is still diarrhea, unfortunately. I hope it's going down into a toilet...
げり
This is a jukugo word that uses the on'yomi readings of the kanji. You should be able to read this on your own.
朝から下痢が止まりません。
The diarrhea hasn’t stopped since morning.