2. A situation or condition favorable for attainment of taking a shit.
3. A good position, chance, or prospect, to use the toilet to void excrement from the bowels through the anus.
During our road trip, we frequently stopped to get gas, food, and of course, to take our shitportunity.
If I miss my shitportunity this morning because the client is late for our meeting, I will be clogged up the rest of the day.