Dr. Johan Nordenstam is a colon and rectal surgeon practicing in Minneapolis, MN. Dr. Nordenstam specializes in the diagnosis and treatment of diseases of the colon, rectum and anus. As a colon and rectal surgeon, Dr. Nordenstam often treats conditions like rectal cancer, colon cancer, hemorrhoids, anal fissures and diverticulitis. Colon and rectal surgeons may be referred to you by your gastroenterologist if your doctor believes you need a surgical procedure.