Haemorrhoids are abnormally enlarged and symptomatic vascular cushions of the anal canal submucosal plexuses of arteriovenous channels, smooth muscle and connective tissue that normally contribute to anal continence. They are classified anatomically as internal haemorrhoids, arising above the dentate line and lined by insensitive columnar epithelium or external haemorrhoids, arising below the dentate line and covered by sensitive squamous epithelium explaining why external haemorrhoids are acutely painful while internal ones are typically painless. Internal haemorrhoids are further graded by degree of prolapse: Grade I (bleed but do not prolapse), Grade II (prolapse on straining but reduce spontaneously), Grade III (prolapse requiring manual reduction), and Grade IV (permanently prolapsed and irreducible). Predisposing factors include chronic constipation, prolonged straining, low-fibre diet, pregnancy, obesity, prolonged sitting and portal hypertension.
Symptoms
The classical presentation of internal haemorrhoids is painless bright red rectal bleeding typically noticed on the toilet paper or coating the stool surface which is the most common symptom prompting consultation. Prolapse of the haemorrhoidal tissue produces a sensation of a lump at the anus, mucous discharge, perianal soiling and pruritus ani. External haemorrhoids present differently acute thrombosis of an external haemorrhoid produces sudden, severe, exquisitely tender perianal swelling that is maximally painful in the first 48–72 hours. It is essential that all rectal bleeding is investigated appropriately to exclude colorectal malignancy before attributing symptoms solely to haemorrhoids, particularly in patients over 40 years or those with associated change in bowel habit.
Diagnosis
The diagnosis is primarily clinical. Digital rectal examination assesses anal tone, excludes low rectal masses and identifies thrombosed external haemorrhoids. Proctoscopy is the definitive investigation for internal haemorrhoids, directly visualising the haemorrhoidal cushions at the 3, 7 and 11 o'clock positions and assessing their grade. Flexible sigmoidoscopy or colonoscopy is performed when there is diagnostic uncertainty, significant bleeding or risk factors for colorectal neoplasia.
Treatment
Conservative management is the foundation of treatment for all grades high-fibre diet, adequate hydration, avoiding prolonged straining and topical preparations (local anaesthetic and steroid creams) to relieve symptoms. Rubber band ligation is the most effective and widely used office-based procedure for Grade I–III internal haemorrhoids, placing a tight elastic band at the base of the haemorrhoid to cause ischaemic necrosis and fibrotic fixation. Injection sclerotherapy with phenol in almond oil is an alternative outpatient procedure for Grade I–II haemorrhoids. Surgical haemorrhoidectomy either conventional Milligan-Morgan open haemorrhoidectomy or stapled haemorrhoidopexy (PPH) is reserved for Grade III–IV haemorrhoids failing outpatient treatment, offering definitive and durable cure. Acute thrombosed external haemorrhoids presenting within 72 hours of onset are best managed by incision and evacuation of the clot under local anaesthesia, providing immediate and dramatic pain relief.