A colon and rectal surgeon is trained to diagnose and treat various diseases of the intestinal tract, colon, rectum, anal canal, and perianal area by medical and surgical means. This specialist also deals with other organs and tissues (such as the liver, urinary, and female reproductive system) involved with primary intestinal disease. Training post-residency is generally two years of fellowship. Certification is through the American Board of Colon and Rectal Surgery.