Diarrhoea

"Diarhhoea, - disorder consisting in the too frequent evacuation of too fluid fæces, sometimes attended with griping pains"

"Often this gripping pain is followed by thrilling, bowel-wrenching influx of sheer pleasure and consummate relief, especially after a desperate dash for the nearest lav." - This is a psychoemotional invertion.

"Diarhhoea, - a plight for the healthy but a boon for the chronically constipated." - and this is a clinical one.