Planning a diarrhea

"Planning a diarrhea" is a humorous way of referring to a planned sick leave from work, especially when it's not backed by actual sickness, but rather to spend paid sick days for things other than sickness.

Diarrhea is used as an excuse for the leave, as it's cumbersome enough to keep one from leaving home, warrants little explanation, and may not require a doctor's note to justify the sick day, as it can go away on its own.