There is often a difference between types of scours, one is the calf simply made a pig of themselves and drank too much milk, and often cutting them back a bit on how much milk they get helps, and often those scours will resolve themselves by itself. The other type of scours when you walk in a barn you can smell this sour yucky smell, and you start looking to see who is sick, cause you know someone is sick somewhere. Maybe I am a suck, but I treat both kinds vigorously. We used to get scour calf boluses, can't remember what the name of them was. One kind had both anti diarrhea and anti bacterial, and if I remember right it had anti coccidiosus stuff in it too.. Would hit them hard with the boluses , and I would give a good shot of trivertrin on top of it too, as it can happen when an animal has a raw gut, bacteria can leave the intestines and go systemic and kill them that way.There may be something out there now that is better than trivetrin, but I found it worked well.
If I figured they had the "runs" too long, i would either try Pepto-Bismol or I would mix up some corn starch and water. If I didn't have any animal probiotics, I would find some human probiotics and open the capsules and mix it in with the cornstarch. Cornstarch slows the bowel waaayy down. Electrolyte,s-- homemade or store bought are important so the heart beat doesn't crash on you. Laugh if you will, but living ways out in the bush and not having access to a vet at the drop of the hat, that is what we would do, and it usually worked.