Bismuth is a non-essential trace element that has been used as an antacid property (Hansen & Penkowa, 2017).

Hansen, P.B., & Penkowa, M. (2017). Bismuth adjuvant ameliorates adverse effects of high-dose
chemotherapy in patients with multiple myeloma and malignant lymphoma undergoing autologous stem cell transplantation: A randomised, double-blind, prospective pilot study. Supportive Care in Cancer, 25, 1279–1289. https://doi.org/10.1007/s00520-016-3522-6