Colonoscopy has completely changed the practice of colorectal surgery, it h
as both diagnostic and therapeutic roles, In diagnosis, it allows direct vi
sualization of the colon and taking of tissue biopsies for histology The co
mmonest therapeutic manoeuvre is polypectomy for bleeding. Colonoscopy is s
afe and, where facilities exist, it should be used as first-line investigat
ion of colorectal disorders.