Yes, that's right. Milk products will help coat their intestines and help stop that bleeding. And yogurt is pretty much always a good idea anyway. That's probably the best thing you can do for them right now
Maxx, that is most likely cocci. Sulmet makes the intestines continue bleeding. You need Corid. Within five days, the cocci should be under control. If it is not, then they should be wormed. Corid is concentrated amprolium and if you can't get it at the feedstore (maybe they can order it?), then get it online. Mine comes in a 16 oz bottle and costs about $20.
You can do yogurt, you can put non fat dry milk powder in their crumble, you can use buttermilk as well to soothe the intestines. Just make oatmeal and pour it in till the oatmeal is soupy.
Is it just the chicks or adults who are pooping blood? Usually adults are immune (to what's in their home soil) unless someone brings in a form of it that wasn't formerly in your soil, either by tracking it in on your shoes or acquiring a new bird who sheds oocysts in the poop that your flock isn't used to. Corid should get it all and be easier on the intestines than a sulfa drug like Sulmet.
Maxx, give them Corrid! Give them some plain yougurt to help (probiotic) reboost them. Also up their protien, scramble some geggs. They are probally gonna get week from being sick and this will help. Just keep on with the medication. I would also clean the coop out with bleach, new bedding and such.
Please keep us posted honey, i know you had a ruff run awhile back with your chickens. Just don't panic, stay strong and focused. We are here with you!!!
Also, change shoes and clothing before going into other coops, cross contamination happens easily.
If you can't get the Corid right away, I would continue with the Sulmet. I had good results with that--and this disease moves fast. Make sure there are no mud puddles in the run and all the water is kept super clean. If you use a dairy product, it must be raw or cultured.
Speckled Hen--wouldn't you agree that Sulmet now is better than Corid in a few days?