Q I’ve been experiencing pain after going to the toilet, and I’ve also noticed blood on the toilet paper. A friend thinks I could have anal fissures. Can you tell me what these are, and how they might be treated? - MS, Huddersfield
A An anal fissure is an ulcer in the tissue which lines the anal canal, which runs from the rectum to the anal opening. The ulcers are thin, elongated tears. They are fairly common, especially among young - and otherwise healthy - people. In acute cases, the fissure develops quickly, and heals almost as fast. A chronic case lasts for longer than a month or so, and recurs. A chronic fissure often develops when a healed fissure tears every time the sufferer defecates.
Fissures affect both sexes equally, and are common in children, too. Some fissures, usually those that occur in the front wall of the anus, appear in women who have given birth, while children who have strained too hard to defecate can also develop them. It has been estimated that up to one-third of all women suffer either haemorrhoids or anal fissures after giving birth (Dis Colon Rectum, 2002; 45: 650-5).
Sometimes, a fissure can arise after anal surgery, such as for the removal of haemorrhoids, or as a result of ulcerative colitis, irritable bowel syndrome, Crohn’s disease or gonorrhoea. An anal fissure may also be caused, or worsened, by anal intercourse. In the main, however, they are caused by the passing of large or hard faeces, which tear off the tissue lining in the anal canal. The problem is often associated with persistent constipation.
The fissure usually begins as a scratch, which fails to heal because of repeated contractions and stretching of the orifice. The tear can cause severe pain during and after bowel movements, and may become infected. Some sufferers may delay going to the toilet because of the pain. This, in turn, can cause further drying and compacting of the faeces, thus worsening the condition.
The main symptom is pain during or after bowel movements, sometimes persisting for several hours. Pain can also occur when any pressure is placed on the anal area, such as when sitting on a chair. Sometimes the pain stops for days or weeks at a time.
Bleeding can occur during or after bowel movements. Often, the sufferer believes they have haemorrhoids - usually because of the bleeding - when, in fact, they have a fissure. The tell-tale sign is pain during or after defecation.
Acute fissures are easier to treat than chronic ones. Sitz baths, suppositories and stool-bulking agents might be tried first, and hydrocortisone may be prescribed to reduce inflammation. However, one study found that sitz baths were of limited benefit. On analysing anal pressures before and after the bath, and comparing the results with those who didn’t have a bath, the researchers found no differences between the groups (Dis Colon Rectum, 1993; 36: 273-4).
Topical nitroglycerin ointment can provide pain relief, and so allow the anus to relax. In one trial of 80 patients, 68 per cent of those given glyceryl trinitrate ointment reported fissure healing within eight weeks compared with just 8 per cent who used a placebo (Lancet, 1997; 349: 11-4).
Although such studies have made topical glyceryl trinitrate a first-line therapy for chronic fissures, an Australian study was more circumspect. By questioning 31 treated patients, the study team found that just 15 of them could be said to be cured; symptoms recurred in four of them. Side-effects were reported by 21 patients, and two of these had effects so severe that they stopped the treatment (Dis Colon Rectum, 1999; 42: 1007-10).