Tincture of opium has been prescribed for, among other things, severe diarrhea.
From the en.wikipedia.org
Laudanum is a tincture of opium and contains no heroin which was not first synthesised from opium until the late 19th century.
From the guardian.co.uk
Paracelsus was also responsible for the creation of laudanum, an opium tincture very common until the 19th century.
From the en.wikipedia.org
After the 1757 territorial conquest of Bengal in India, the British had access to opium, which was used in western society as a tincture added to water for purification.