Rooster Cannot Poop

Hello! I have a 3 year old bantam silky rooster. About a week ago I noticed he had a lot of poop stuck to his butt, but it did not seem like a huge issues. Then, yesterday, I saw him squatting and trying to poop but was not able to. He was making a very sad clucking noise and i could tell he was in pain. He also did not crow in the morning which is unusual for him. I could tell he was in pain so I caught him and soaked him in warm soapy water for about half an hour, hoping the poop would loosen. Upon inspection I noticed that the poop was not stuck to his feathers around his butt, but was actually crusted over his anus. His anus was swollen and protruding. Even after soaking him and applying vaseline in hopes that the poop would loosen up and I would be able to wash it off, this did not happen. It was evident that if I tried to pull the poop off him it would tear his skin and he would bleed. I managed to soak enough poop off that there was a small hole through which he could poop, but there was still a lot of old poop crusted on his anus. He pooped at least twice last night and I was hoping that the problem was solved, but this morning I saw him squatting and making painful clucks again as he strained to poop but could not. Please help me, I don't know what else to try and I am worried he will die if he cannot poop.