ABC of colorectal diseases. Anal fissures and fistulas.

B D HancockAnal fissures most commonly affect patients aged between 30 and 50.They are equally common in men and women.A fissure is a split in the lower half of the anal canal extending from the anal verge towards the dentate line.Most fissures are posterior, but anterior ones are often seen in women.The cause is not clear, but a fissure often starts after an attack of either diarrhoea or constipation.Some heal spontaneously but many become chronic, r tl-r'e.S'W , k -v *In controlled trials anal dilatation has been shown to be slightly inferior to lateral subcutaneous jji: 0~K;d4.sphincterotomy with respect to recurrence rate and the incidence of minor complications such as lack of control of flatus.Permanent cure can be Anal pressures before and after procedures for fissure.The high pretreatment expected, but a long term high fibre diet is values may induce local ischaemia sufficient to prevent spontaneous healing.advisable.