Corid aka Amprolium is an inhibitor of thiamine (vitamin B1). Rapidly dividing coccidia have a high requirement for thiamine and corid prevents it from happening.
However, corid wont treat coccidia that causes blood in feces caused by two types of Eimeria coccidia. A sulfa drug will then be needed.
It's not worms, it's shed intestinal lining. I highly recommend that you get your chicks started on Corid 9.6% liquid solution. Dosage is 9.5ml per gallon of water for 5-7 days. You can make the one gallon solution, then pour it into the smaller waterer(s). Make it fresh daily and dont add...