I think the vast majority of women squeeze out some poop when they are pushing. After all...its all so close together down there. Its not a big deal, and you may not even know you're doing it. The hospital table (or your bed, or your floor, or tub) will be prepped to receive some mess - its likely you'll just poop on the chux pads or whatever, and the nurse/midwife/doctor/doula will just whisk it away.