This section is from the book "Materia Medica And Therapeutics Inorganic Substances", by Charles D. F. Phillips. Also available from Amazon: Materia medica and therapeutics.
Prof. Gubler, having remarked the analogous effects of the oxides of zinc and of bismuth, suggested the substitution of the former when expense was an object, and experience has proved that the zinc compound will often act in an extremely satisfactory manner in relieving gastric pain, especially when this is followed by diarrhoea of undigested food; it has, however, more tendency to nauseate than the bismuth salt. The dose should commence at 1 gr., and not exceed 3 gr., and should not, as a rule, be given on an empty stomach.
Dr. Brakenridge, of Edinburgh, was one of the first to draw attention to the value of zinc oxide in infantile diarrhoea (Medical Times, i., 1873), and I have, in common with many others, found it an efficient and non-irritant astringent.
In chronic diarrhoea, and even in dysentery, the oxide has acted very favorably (Bulletin de Therapeutique, March, 1877), but the sulphate has more decided powers.