Actually,
@jessejeanne , you may be right about it being a crop problem. Though I prefer to use chilled coconut oil, Colase, miconazole, or even acidified copper sulfate to treat crop problems, Epsom salts can be used, according to some poultry colleges, to flush a crop. Here is an example of that:
https://extension.umd.edu/resource/common-crop-issues-backyard-chickens/
Next time you suggest a treatment, just post the whole article or link. We all are entitled to giving our advice here, so keep it up. We may disagree with you, but if you have a link to back it up, it is perfectly welcome.