HELP!! Hen acts like she is dying!

[cassbickford]

HELP!!! A have a hen who was perfectly fine yesterday and today she looks like she's dying. She was around all day yesterday acting normal and then at lock up time last night she was not around so I locked up without her thinking that she was just in a bush or tree. When I went to let the girls out this morning, she was standing outside the coop and was wobbly. I checked her over thinking maybe she was attacked, but there is no signs of that. She went right into the coop and laid down in a nest box. I just went in to check on her and she has a runny nose and mustard colored loose stool stuck around her vent. Any ideas?!