Streptococcus bovis bacteraemia requires rigorous exclusion of colonic neoplasia and endocarditis.

Twelve patients presented to the hospitals of the Auckland Hospital Board with bacteraemia caused by Streptococcus bovis in the years 1979-84. Ten had endocarditis, affecting homograft valves in two cases and the tricuspid valve in one case. Of nine patients who underwent investigation of the large bowel, only one did not have a colorectal tumour. Three had colonic adenocarcinoma and three had colorectal villous adenoma. Two, including a patient with acute hepatic failure from alcoholic cirrhosis, had colonic adenomata. Colonoscopy provided a tissue diagnosis of colorectal neoplasia despite negative radiological studies in three patients. Bacteraemia due to S. bovis should prompt rigorous investigation to exclude both endocarditis and tumours of the large bowel.