X2 on Corid not treating worms. Worms can be a cause of blood specks in droppings, but you may never actually see worms without having a fecal float done by your vet. For worming, Valbazen or SafeGuard Liquid Goat Wormer are the best most effective for most worms.
Can you post any pictures of your hen’s poop? Yellow urates in the poop can be a sign of liver disease. I had one hen who I did a necropsy on at home who had fatty liver disease, and who had 2 inches thick fat and a large blood clot on her tan liver. None of the others have ever had that, and I do necropsies on most of the ones who have died over the years. Fatty liver can have numerous causes, such as genetic predisposition, poor diet high in carbs and fat, exposure to aflatoxin or funguses, and many other.