After 2 weeks of trying every other sour crop treatment with no signs of improvement, I got desperate and tried something unproven. After learning that sour crop is a form of yeast infection and reading that some others had treated with Clortrimazole (found in Lotrimin and Mycelex) , I decided to try it. However, I was unable to locate any in my small town. So, with the hen in danger of dying already, I purchased a generic box of Monistat 3 (for about $5) which contains Miconazole Nitrate and decided to give it a try. The box contained 3 suppositories and a tube of external cream. I cut the suppositories in thirds and fed the hen one third each morning, and one third each evening until all 9 pieces were gone. I continued syringe feeding yogurt, boiled egg yolk, and gruel made from finely ground chicken feed and water. I am happy to say our hen has made a full recovery! I thought others might find this helpful.