The present invention relates to the a bismuth-based composition, particularly involving the use of bismuth ions, particularly the Bi+3 ion, for prevention and/or treatment of the haemolytic uremic syndrome, with the invention also relating to the use of a bismuth ion in the manufacture of a medicament for the prevention and/or treatment of an infection caused by a Shiga-toxin producing Escherichia coli strain, as well as to a method for preventing and/or treating the haemolytic uremic syndrome comprising administering bismuth ions to a patient in need thereof, and a method for inhibiting dissemination of the gene encoding virulence factors of a Shiga-toxin producing Escherichia coli strain in animals and humans.