An antibacterial with very few bibliographical references which is used with little evidence of its efficacy (N.A.L. Prescrire 2004 and 1999) in the treatment of acute gastroenteritis of bacterial origin. Since the last update we have not found published data about its excretion in breast milk. It has a very low oral bioavailability, due to low or zero intestinal absorption (Armstrong 2015), making it unlikely its would pass into breast milk. Its low oral bioavailability would also further complicate its passing into the infant’s plasma via ingested breast milk, except in premature babies and in the immediate neonatal period during which there may be greater intestinal permeability.