Rectal Bleeding

Rectal bleeding is very common in western society communities and is most commonly caused by haemorrhoids. Because it can be difficult at times to be sure of the origin of the blood, investigation may be required to ascertain the exact cause (and it can usually be dealt with in a simple manner).

Observation
It is most important that ANY rectal bleeding be reported to your family doctor. Some simple observations may greatly assist in determining the likely origin of the blood. Take note of its frequency, the amount and whether it is seen on the toilet paper or underwear or actually in the toilet (or both). If it is seen in the toilet, is it splattering the toilet bowl separately from the bowel motion (even if at the same time as the motion is passed), or is it mixed through the matter (or indeed is it just coating the outside of the formed stool). These small details can be very important and it is therefore a good practice for everyone to observe their stools to be able to report on such details.

Just a glance is all that is required!
Any other changes or abnormalities associated with the bleeding should also be carefully recorded. eg. a change in the usual pattern of frequency or consistency of bowel actions, the presence of associated abdominal bloating and discomfort or anal pain with the passage of the motion and a feeling of incomplete evacuation may all be important signs to observe.

Causes
Haemorrhoids (“piles”) are present in everybody as they are simply small bundles of veins which “fine-tune” anal muscle control. Strain, such as in pregnancy or due to constipation will cause the connective tissue fibres holding the veins onto the underlying muscle of the bowel wall to shear away, causing prolapse of the bundles into the anal canal and exposing them to strain forces which can tear the overlying bowel lining and thus cause bleeding. If the haemorrhoids protrude enough, vigorous wiping after bowel action may also cause bleeding. Additionally, mucous discharge onto the anal verge may cause itch (pruritus ani) which can be troublesome.
Anal fissure will cause bleeding due to the tearing of the skin lining the anal canal. Their will usually be significant accompanying pain during the passage of a motion.

Inflammation of the lining of the large intestine (Called proctitis if just above the anus and colitis if more extensive) will cause bleeding but usually in association with loose and frequent bowel actions and often with a lot of mucous discharge).
Severe bleeding in large quantities is uncommon and is mostly due to either an abnormality of some tiny blood vessels in the bowel lining (AV malformation or angiodysplasia) or from a diverticulum (a small pouch extruding from the bowel wall due to years of pressure from passing firm bowel motions). Diverticula are very common but bleeding from them is relatively rare.

Bowel cancer can mimic haemorrhoidal bleeding or it can present as blood in small quantities mixed through the motions. It can however grow near the upper part or beginning of the large intestine and “drip” into the motions in such small amounts that it is not detected until the patient presents with symptoms of iron deficiency anaemia (such as shortness of breath and tiredness).

Polyps are small “warty” growths which occur on the surface lining (mucosa) of the intestine. They are very common, most do not become malignant (ie turn to cancer) but the large majority of bowel cancers are derived from polyps which have grown to a large size and as the cells divide they become abnormal and, eventually, develop into cancer. A polyp of less than 1 cm in diameter has a less than 1% risk of cancer. A polyp of 2 cm has a 40% chance of cancer. Consequently it is ideal to remove polyps before they can become large enough to turn to cancer

Investigations
The most important assessment is the history of the details of the bleeding and associated factors which will be taken by your doctor. The minimum examination required is a gentle examination of the anal canal and this will probably be followed by assessment with an instrument to look into the rectum (lower bowel) and perhaps further into the large intestine.

The decision as to whether to look further will be made by your family doctor and may necessitate referral to a specialist colorectal surgeon. Many patients will undergo a short examination of the rectum, possibly followed by some simple treatment for haemorrhoids (if shown to be the cause) which may involve the application of some tiny rubber bands to the haemorrhoids on the insensitive lower bowel lining (where there are no nerve fibres) such that they strangle, die and drop away painlessly. This is a simple office procedure.

Other factors may suggest colonoscopy (examination of the large intestine with a flexible fibreoptic video telescope) in order to be sure there is no pathology higher up. If present, most polyps can be removed through the colonoscope at the same time. This procedure is carried out under sedation such that there is no knowledge of the procedure but the risks of general anaesthesia are avoided. Colonoscopy takes about 20 minutes and some time in recovery before discharge.

Remember
Rectal bleeding is common.
Most rectal bleeding is harmless.
Rectal bleeding may be an early warning sign of important pathology.
Pathology found early has the greatest chance of complete cure.