About a month ago I bought 5 healthy chicks from a local feed store. They are all doing great. A week ago I went to the same feed store and found that they had day old bantams. I bought 5, and then the next day went back and bought 3 more. The same day that I brought home the 3 new babies I noticed one of them had blood in its feces and its vent started to protrude. I never noticed any more blood but the protrusion was getting worse. It acted completely fine but it would get some diarrhea sticking to its behind so I would clean that. After about 4 days it died, and then I noticed a couple of other chicks started to get diarrhea. This is when I started to panic. I had one of the month old chicks in with the babies because of space. Her droppings were completely normal so I moved her out and quarantined her. I watched her for a couple of days and saw no signs of anything so I moved her back in with her old flock. I quarantined the two sickest chicks with diarrhea. Started them all on medicated feed and added ACV to their water. One sick chick died yesterday, the other is showing signs of improvement (up & eating... actually trying to fly out of the box now), but I am still seeing some loose droppings in the box with the remaining chicks. Some of its kind of mucousy. Kind of a tan color. My first thought was coccidiosis but can chicks this young get that? Could it be e-coli? Pullorum? I have free range adult chickens outside. I am a nervous wreck. I don't know what to do. :/