ABSTRACT
Haemorrhoids are one of the most common conditions to afflict mankind, but it is impossible to give an accurate figure for their prevalence. Although many patients present with symptomatic disease, many do not and some never have symptoms. Beneath the epithelial lining of the anal canal, there are rich plexuses of vascular tissue. These serpiginous vessels have been called the ‘corpus cavernosi recti’. They connect arteries to veins without intervening capillaries. The role of the vascular cushions in the process of normal rectal evacuation is incompletely understood, but straining at defaecation seems important in the development of haemorrhoidal disease. It is readily observed during anoscopy that the cushions rapidly empty and fill. In the child and healthy adult, the submucosal vascular cushions are supported by the pecten band and by the muscularis submucosae. The vascular cushions and the muscularis are normally only loosely attached to the underlying circular muscle.
