2 Clinical need and practice
2.1 Haemorrhoidal tissue is a normal component of the anal canal and is composed predominantly of vascular tissue, supported by smooth muscle and connective tissue. It functions as a compressible lining that allows the anus to close completely. Internal haemorrhoids (also known as piles) are located beneath the lining of the anus and occur when the haemorrhoidal tissue of the distal rectum and anal canal prolapses. Internal haemorrhoids are usually classified according to the degree of prolapse, although this may not reflect the severity of the person's symptoms. First-degree haemorrhoids bleed but do not prolapse. Second-degree haemorrhoids prolapse on straining during bowel movements, and reduce spontaneously. Third-degree haemorrhoids prolapse on straining and require manual reduction. Fourth-degree haemorrhoids are prolapsed and cannot be manually reduced.
2.2 A number of factors are known to be associated with the development of haemorrhoids, including increasing age, pregnancy and childbirth, chronic constipation, chronic diarrhoea, and family history of haemorrhoids. Estimates of the proportion of the UK population affected range from 4.4% to 24.5%. In 2004–5, approximately 23,000 haemorrhoidal procedures were carried out in England, of which approximately 8000 were excisional interventions.
2.3 Internal haemorrhoids may cause anal itching and irritation, bleeding during bowel movements and perianal pain. They sometimes protrude from the anus during bowel movements or may prolapse or extend outside the anus. External haemorrhoids can also occur. These are located near the anus and, although they cannot prolapse, may bleed if ruptured.
2.4 First- and second-degree internal haemorrhoids are generally treated by changing bowel habit, diet and lifestyle, and by using stool softeners or laxatives. For second-degree haemorrhoids, injection sclerotherapy, rubber-band ligation or infrared coagulation may also be used. Surgical haemorrhoidectomy is usually the treatment of choice for third- and fourth-degree haemorrhoids, prolapsed second-degree haemorrhoids that have not responded to non-surgical interventions and second-degree haemorrhoids with full circumferential involvement. Surgical haemorrhoidectomy is usually performed by the Milligan-Morgan (open) or Ferguson (closed) procedure. The Milligan-Morgan procedure involves dissection of the haemorrhoid and ligation of the vascular pedicle. The wounds are left open to heal naturally. The Milligan-Morgan procedure is thought to be relatively safe and effective for managing advanced haemorrhoidal disease, but because the anodermal wounds are left open healing is delayed, which may result in discomfort and prolonged postoperative morbidity. The Ferguson procedure is a modified version of the Milligan-Morgan technique, in which the wound is closed with a continuous suture to promote healing. A number of postoperative complications are associated with surgical haemorrhoidectomy. The short-term complications include pain, urinary retention, bleeding and perianal sepsis. Long-term complications may include anal fissure, anal stenosis, incontinence, fistula, and the recurrence of haemorrhoidal symptoms.