For those of you who have heard me say this before - its from the old Dr. Whitney vet book (orig published in 1898) Cheap hamburger, brown rice and tomatoes, in water - boil it until the rice is mushy. You can use stewed tomatoes as it's the pectin around the little seeds that is the binding agent. Feed in small amounts.
re: pepto vs Immodium Pepto does have an antibacterial that Immodium does not have so it really depends on what might be going on in the gut.
You might also - in extreme circumstances need to add some pedilyte for electrolites (find it in the baby food aisles)
Make sure it's not camphylobacter - as that needs a course of antibiotics AND can transmit to humans and is contagious long after symptoms are gone.