Swollen veins in the lining of the anus. Sometimes these veins protrude outside the anal canal, in which case they are called prolapsing haemorrhoids. Straining repeatedly to pass hard faeces is one of the main causes of haemorrhoids. Haemorrhoids are also common during pregnancy and just after childbirth. Rectal bleeding and discomfort on defaecation are the most common features. Prolapsing haemorrhoids often produce a mucous discharge and itching around the anus. A complication of prolapse is thrombosis and strangulation; this can cause extreme pain. Diagnosis is usually by proctoscopy. Mild cases are controlled by drinking plenty of fluids, eating a high-fibre diet, and establishing regular toilet habits. Rectal suppositories and creams containing corticosteroid drugs and local anaesthetics reduce pain and swelling. More troublesome haemorrhoids may be treated by sclerotherapy, cryosurgery, or by banding, in which a band is tied around the haemorrhoid, causing it to wither and drop off. A haemorrhoidectomy is generally required for prolapsing haemorrhoids.


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