Haemorrhoids, also known as piles are rather like varicose veins in the canal of the anus. Here, just under the mucous membrane inner lining, is a considerable network of veins extending upwards for an inch or so from the level of the skin to just above the anal canal, where it joins the rectum. When the veins of this network become swollen with blood, haemorrhoids occur. The vein swelling can affect the part of the network just above the anal canal, where it is less well supported by the muscular ring (sphincter), and this causes internal haemorrhoids. Or it may affect the veins at the lower end of the canal, just under the skin, causing external haemorrhoids. Some people have both.

Haemorrhoids are a common problem and affect around 50% of people at some time in their life. Although uncomfortable and embarrassing, it is not normally a serious condition.

Symptoms

The common symptoms of haemorrhoids are:· 

• Itching around the anus
• Signs of blood (bright red) on toilet paper after a bowel motion
• Soreness and discomfort during and immediately after a bowel motion
• A visible swelling around the anus
• A feeling that your bowels have not been completely emptied

Sometimes haemorrhoids inside the anal canal protrude outside the anus. These are known as prolapsed or prolapsing haemorrhoids. At first, the haemorrhoid may go back in by itself, but later you might need to push it back in yourself using your finger.

Protruding haemorrhoids can lead to skin irritation and discomfort and there is usually mucus discharge from the irritated mucous membrane. Haemorrhoidscan become inflamed and swollen, but are rarely very painful, unless associated with an actual splitting of the anus (Anal fissure).

If haemorrhoids are causing a lot of pain and discomfort, then you should see your GP.

Causes

Haemorrhoids are thought to be caused by constipation. If you have constipation over a period of time and often have to strain to pass hard stools, this can damage the lining of the anal canal. If this happens often enough, the veins may lose their normal support and protection. Some people are thought to have veins especially liable to this kind of injury. This is probably just a matter of chance anatomical variation. Haemorrhoids are not caused by sitting on cold hard surfaces, prolonged standing or sedentary work.

The veins around the anus drain into larger veins that carry the blood through the liver and up to the heart. This part of the system of large veins has no valves in it, and the whole weight of the blood bears down on the lowest veins in the system, which tend to stretch. Anything restricting the free upward flow of blood through these veins leads to an increase in pressure in them. This is why haemorrhoids are so common in pregnancy.

Treatment

For most people with haemorrhoids, the condition is mild and can be treated with over the counter (OTC) medicines that tackle the symptoms. The haemorrhoids will eventually go away without treatment. Haemorrhoids caused by pregnancy will usually go away after the baby has been born. Symptoms can be treated with agents that soothe the pain, usually in the form of ointments or suppositories. Corticosteroids are often combined with local anaesthetic agents and are helpful for short-term use (up to 7 days). They are not recommended for long-term use or for use in children.

Where haemorrhoids are more serious, surgery or other treatments may be necessary. Surgical removal of piles is called haemorrhoidectomy. Most piles are not treated by haemorrhoidectomy, because an effective alternative procedure is rubber-band ligation. In this method, a tight rubber band is placed round the neck of the pile so that its blood supply is cut off and it shrivels. Other methods include injection with a solution that causes the blood to clot, destruction by freezing and treatment with a laser.

Haemorrhoidectomy is reserved for those cases in which the piles are large and internally placed. The operation involves tying a tight string (ligature) around the base of the pile to control bleeding and cutting off the outer part. This leaves raw areas of bowel lining which, over the course of three or four weeks, become covered with the normal inner-surface membrane (epithelium). During this period, the stools are kept soft by the use of water-retaining agents such as methyl cellulose.

The results are generally good and only a small proportion of people operated on have recurrent symptoms. During the immediate post-operative period, however, men may find difficulty in passing urine for a time and there may be a slight tendency to incontinence.