Streptococcus gallolyticus is a microorganism belonging to the Streptococcus bovis I group isolated in humans, bovines and equines pigeons, among other animals. Streptococcus bovis is a Streptococcus strain found in the rumen, and has been isolated in the milk of animals with mastitis. The authors describe a case of an adult immunocompetent patient with underlying valvular heart disease, with bacteraemia and infective endocarditis by Streptococcus gallolyticus, in whom adenomatous colonic polyps with dysplasia were identified.