Description: Although rectal and perianal complaints are among the most common seen by primary care physicians, surgeons, and gastroenterologists, the wide variety of disorders associated with these complaints are, in general, poorly understood. Additionally, a variety of newer diagnostic techniques, such as endoscopic ultrasound, mannometry, and magnetic resonance imaging, are now being employed for the evaluation of these disorders. Finally, new pharmacotherapies, including immunosuppressants and topical therapies as well as new surgical treatments, have emerged. These are described in a clear, user-friendly manner.