One of our brahma chicks was like this. She was constantly making this intense chirping noise, putting her wings up, and pushing -- but nothing would come out.
It got pretty bad -- where she was just hanging around looking miserable with poop hanging out of her butt. We did several things:
- gave her a warm bath. Just held her in a warm bowl of water, and then afterward gently blow-dried her (on low). Both of these events caused her to poop
- gave her molasses tea-- water mixed with molasses
- gave her yogurt
- gave her bread soaked with olive oil
- wiped her bottom when when she had poop hanging there.
I don't know what worked, but she is 8 weeks now and totally fine-- although her growth was stunted. She is half the size of our biggest girl who is the same age.
I think it was eating the pine chips, or else not being outside early enough, scratching around in the dirt.