well you can poop in the middle of labor everything is pretty much squeezing down in that one area as you get closer so I wouldn't put it past to have diarrhea before labor and really could mean you won't poop in labor! lol
Yup i had it like a week before i went into labor after all the diarrhea and vomiting feeling i got constipated and didnt poop for two days then went into labor