Cause of haemmoroids

Unknown, most popular ideas is chronic straing due to inadequate roughage in the diet. The following may play a role;

1. Poor return of venous blood through the superior rectal veins; Straining to pass water or stool, pregnancy, portal venous hypertension
2. Sphincter dysfunction (hypertonicity); Increased shearing forces on the anal cushions Decreased blood return through the intersphincteric shunts
3. Damage to the connective tissues from repeated swelling; this permits prolapse

There is no good evidence that a rectal tumour will cause haemorrhoids; this does not mean that the possibility of there also being a rectal tumour should be neglected.