Are all the chicks shedding intestinal lining, any blood? If so, mix buttermilk or even milk in their feed (make it milky). Either will coat the intestinal lining to slow the damaging effects of coccidia until the corid arrives. Ensure feeders and waterers are feces free at all times, clean...
Stop the oatmeal and just feed them the chick starter.
Shed intestinal lining is normal on occasion but if it's frequent, I recommend getting them started on Corid. If you see more blood, definitely get them on Corid.