Looks like shed lining, is it a one off or have you seen this for awhile? Can you put it into a cup of water and confirm if it's blood or lining? From my observation, young birds will shed lining as they grow through milestones. It's usually a poop or two for a couple of days and then stops. If it's excessive it could be coccidiosis which would be treated with corid. If it's worse then you'll need antibiotics.
How old is this chicken? Have you wormed them lately? Coccidiosis or worms can cause the red blood. I would consider worming with Valbazen or Safeguard, and giving some Corid, unless you can see a vet to have a fecal float on some fresh droppings.