Pathogenesis (what causes hemorrhoids)
The anal canal and the lower rectum have a lumen lined by three fibro vascular cushions. Within each cushion is a venous plexus fed by artero-venous communications. The internal hemorrhoid plexus receives its blood supply exclusively from the terminal branches of the superior rectal artery.
There are many theories on the pathogenesis of the hemorrhoid disease, like the “vascular hyperplasia theory”; the “mucosal sliding down” theory, the”varicosity” theory. In fact, there are many factors that contribute to develop “pathological” hemorrhoid cushions.
These alterations can be caused or favored by the following conditions:
- Environmental factors
- Straining during defecation
- Low fiber diet
- Sedentary lifestyle
- Other conditions:
- Deterioration of connective supportive tissue
- Associated diseas