Anorectal bleeding refers to any bleeding that occurs from the back passage. It is an extremely common condition. In the large majority of cases, it is coming from the anal canal and is not serious at all. Doctors try to tell the difference between anal bleeding (coming from the back passage) and rectal bleeding (coming from further up the bowel).
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What is anal bleeding?
Anal bleeding is nearly always due to benign conditions, usually haemorrhoids (“piles”) or fissures.
The blood is usually bright red and fresh as though you had been cut. It usually occurs when your bowel has been moved but is sometimes seen as a stain on the bedclothes or underwear.
When it occurs with bowel movement, it may be slight (seen as a smear on the toilet paper) or heavier when it discolours the water in the toilet bowl. Sometimes, it will splash the bowl or even drip into the toilet after the motion has passed.
Although the blood may coat the motion, it will not be mixed in with it
Bleeding from a fissure may be quite painful while hemorrhoids are either painless or associated with only mild discomfort.
What is rectal bleeding?
When the blood is dark or clotted or mixed in amongst the bowel motion, it is possible that the blood is coming from further up inside the bowel.
While many of the causes of this type of bleeding are still innocent, it may be due to a more serious disease. The most serious of all is cancer of the bowel but it may also be coming from polyps arising from the bowel lining or inflammation of the bowel.
All of these more serious conditions can be satisfactorily treated and cancers can be cured. However, it goes without saying that the sooner they are identified the more likely it is that they can be effectively treated.
When should you report bleeding from your back passage?
You should report almost any episode of bleeding to your doctor if you have not had prior episodes.
However, if it is bright red and associated with short-lived pain and passing a hard stool, it is highly likely to be due to a small tear in the back passage.
It is particularly important to report if it is associated with a change in your normal bowel pattern or a sense of incomplete emptying of your bowels.
What will your doctor do?
Having asked you a number of questions, he or she will want to examine your back passage.
You will be asked to lie on your left side, to allow the doctor to have a careful look at the skin around the back passage. He will then insert a gloved finger into the back passage. This is done gently and is much less painful than many people imagine.
Depending on whether you are being seen by your GP or by a specialist, further tests may include proctoscopy, rigid sigmoidoscopy, flexible sigmoidoscopy, colonoscopy or CT scans.
What do these tests involve and what are they for?
- Proctoscopy allows direct inspection of the anal canal to see if there are haemorrhoids present. It feels almost the same as the examination with the finger. Many GPs will do proctoscopy in the surgery but may refer to a specialist if they think that one or more of the other tests are required.
- Rigid sigmoidoscopy, flexible sigmoidoscopy and colonoscopy are all tests where the lining of the bowel is inspected directly via a telescope. They differ from each other in how much of the bowel can be seen, how long they take and where they are done. The specialist will advise which of the tests is required and explain what is involved.
- Colonoscopy is a test which allows the doctor to inspect the whole length of the bowel.