Haemorrhoids are a group of vessels in the anal canal. They are frequently responsible for bright red painless bleeding from the anal canal. This can happen if they are scratched, or if they become enlarged – usually from sitting for too long on the toilet and straining to pass a motion. Haemorrhoids tend to become smaller and bleed less if a high fibre diet is adopted.
Too much straining can lead to the haemorrhoids hanging a bit below or just outside the anal canal. This can lead to them being scratched, or them enlarging, either of which can lead to bleeding.
Only on the rare occasion that haemorrhoids prolapse very badly do they cause pain.
Minor haemorrhoidal symptoms usually get better with a high fibre diet, mainly because it leads to less time spent on the toilet.
Further bleeding can be decreased by either banding or phenol injection of the haemorrhoids.
On rare occasions haemorrhoids need to be excised or hitched up and sutured.
It is not possible to distinguish haemorrhoidal bleeding from a colonic or rectal cancer bleeding so this leads to most people with bleeding from the bottom needing to undergo a colonoscopy.