Insurance Shit
When you take a shit either A: so you don't have to later on while there is no time or B: are not sure if you have to fart or have to shit so you go do it on the toilet.
A: "Dude, I'm not sure my bowels will make it the entire road trip without me taking an insurance shit before we leave"

B: "Dude, I'm not sure if I have to fart or crap so I'd better go take an insurance shit just in case"