Introduction

Improvements in our understanding of the anatomy of haemorrhoids have prompted the development of new and innovative methods of treatment. Unfortunately confusion still exists among lay people and doctors, who misuse the terms haemorrhoids and piles to cover a variety of complaints. This has led to estimates of prevalence varying from 4.4% among adults in the United States to 36.4% in general practice in London.1 2 This article describes the pathogenesis of haemorrhoids and management strategies (fig 1).

Methods

We retrieved evidence based articles from the Medline database and Cochrane Library under the MESH subheading “hemorrhoid.” We included randomised controlled trials with valid end points and meta-analyses.

Pathogenesis

The anal canal has a triradiate lumen lined by three fibrovascular cushions of submucosal tissue. The cushions are suspended in the canal by a connective tissue framework derived from the internal anal sphincter and longitudinal muscle. Within each cushion is a venous plexus that is fed by arteriovenous communications. These specialised vascular structures allow for enlargement of the cushion to maintain fine continence. In health as in disease the anal cushions appear in the right anterior, right posterior, and left lateral positions.3

Fragmentation of the connective tissue supporting the cushions leads to their descent. This occurs with age and the passage of hard stools, which produce a shear force on the framework. Straining produces an increase in venous pressure and engorgement. The prolapsed …