Dear Jackie: I just remembered that the usual anti-diarrhea
preparation was "paregoric". The etymology is interesting.
paregoric

SYLLABICATION: par·e·gor·ic
PRONUNCIATION: pr-gôrk, -gr-
NOUN: A camphorated tincture of opium, taken internally for the relief of diarrhea and intestinal pain.
ETYMOLOGY: Late Latin pargoricus, soothing, from Greek pargorikos, from pargorein, to talk over, soothe, from pargoros, consoling : para-, beside; see para–1 + agora, agora; see agora1.

Incidentally, the "camphor" made it extra nasty to take.
Maybe it was intended as a deterrent to misuse.