Rooster keeps getting impacted crop/sour crop?

[Zombirr]

I have a young New Hampshire Rooster who keeps getting sourcrop/ impacted crop and has a very discolored comb.

This started about a week ago when we noticed he was acting weird, we found out it was impacted crop and my brother treated him.

He stared acting better and running around more but his crop won't drain right, and he still has a very discolored comb?

I will also add on that he was kept in a pretty small chicken tracker with his brother. We were supposed to be boarding him and his brother for a few days and then it turned into a couple months,, and we haven't heard from the guy.
I'm not sure if keeping him in a small space may have giving him respiratory issues or not but I thought I would mention it.

 

[coach723]

Sour and impacted crops can have multiple causes, narrowing it down can take some time. Being a roo eliminates some of them. These are good articles to help:
https://www.backyardchickens.com/ar...ntion-and-treatments-of-crop-disorders.67194/
https://www.backyardchickens.com/ar...w-to-know-which-one-youre-dealing-with.73607/
If you have a vet that will run a fecal for you, I would do that. Internal parasites can cause crop issues.
Most respiratory issues are viral or less commonly fungal. If you are seeing symptoms of respiratory problems then a vet can test for those also. Some are chronic and the birds are carriers for life and symptoms will come and go.