I remember my Mum giving me, and indeed my Siblings Kaolin and Morphine when we had tummy upsets, and it worked. It certainly calmed the painful spasms, as indeed it would have, due to the morphine. There was also another product that was equally as good that came in a small bottle which I think was called 'Collis Brown tincture'. You added a certain amount of drops to a small glass of hot water.
I believe that this was withdrawn after many years because that too contained Morphine, but again, it worked.
Years ago, I saw a young man go into a Chemist and ask for Kaolin and Morphine. The Chemist who served him shook the bottle hard to mix the contents as they separated after standing a while. When I asked why he did this, he explained that drug addicts liked to drink the Morphine which floated to the top, therefore it would not be possible to drink it until the contents had settled again, which would take quite a while.