Did you check her for a stuck egg? If there is one stuck she may not be able to poop. Vaseline on a latex gloved finger inserted no more than 2 inches...you will feel an egg if there is one there. Is that hard poop inside her vent in the picture? Were you able to clean it out? The only other thing i can think is a partial prolapse when her inards stick out of the vent...you would need to gently push it back in and keep her seperated in a dark place. Hemmeroid cream can be helpful to reduce swelling and you may need to continue to push back inside.