Hemorrhoids are mucosal vascular cushions in the anal canal, which are present in all individuals. They aid in closure of the anal canal at rest and help prevent incontinence to stool and flatus. They are classically located in the left, right posterior, and right anterior positions (from the patient perspective). Only when these cushions of tissue become symptomatic do they become what the general public refers to as "hemorrhoids." Hemorrhoidal disease is common with 1 million new cases a year and prevalence in the United Sates of 8.5 million people. These cases account for 1.9 million ambulatory visits and 168,000 hospitalizations a year [1]. © Springer-Verlag London Limited 2010.
