That is pretty bloody. I might get some Corid (amprollium) powder or liquid from your local feed store. If you see another poo like that, or if she acts sleepy, hunched, or is not drinking, then I would start treatment for coccidiosis. Dosage is 1 1/2 tsp of the powder or 2 tsp of the liquid per gallon of water changed daily for 7 days. Treat all of them at once. It is a safe medicine to use.
We've been feeding medicated starter and started Corid when we found the bloody poo.
Her next 2 poops after this picture was normal though.
Could it be something else or just continue with the Corid treatment?