Around 30% of patients with Crohn's disease will suffer perianal complications of the disease, such as:

1. Skin lesions

These include:

• excoriation (redness and soreness) due to drainage and diarrhoea
• skin tags
• ulcers and abscesses just beneath the skin

2. Anal canal lesions

These include:

• Fissures (painful cracks)
• ulcers
• stenosis (narrowing of the passage)

3. Fistulas

These may be:
• low
• high
• recto-vaginal

Approximately 10-15% of patients with Crohn's disease initially present with perianal symptoms. Further investigation confirms the diagnosis.

Treatment usually involves treating the underlying disease thus improving perianal symptoms. These conditions, particularly skin tags and fissures, can often look unsightly but apart from occasional bleeding, may be relatively painless. Under these circumstances surgery should be avoided at all costs and with the aid of conservative medical treatment you should try to live with the condition.

However, to determine if more extensive intervention is required, further investigations may need to be carried out. These could include:

a) MRI scanning

This is one of the most accurate techniques for showing the extent of complex fistula tracts and detecting unsuspected abscesses. It is a painless procedure without risk of radiation. However, it is costly and not available at all hospitals.

b) Sigmoidoscopy

This may be either with a rigid or a flexible tube. The advantage of the flexible tube is that it can view further but needs to be carried out in the Endoscopy Department, rather than at an out-patient clinic.

c) Examination under anaesthetic

It is sometimes too painful to perform a successful examination and therefore an anaesthetic may need to be given in the operating theatre.

Treatment

This tends to be relief of symptoms medically, with minimal surgical intervention if unresponsive to this.

Medical management

1. Drugs

These could include:

• Antibiotics used to control infection and assist healing, (e.g. Metronidazole, Ciprofloxacin, Tetracycline). There is often a relapse when medication stops, so smaller maintenance doses are usually needed.

• Anti-inflammatory drugs (e.g. Salazopyrine, Mesalazine, Prednisolone). As with antibiotics there is often a relapse when medication stops, so smaller maintenance doses are usually needed.

• Immunosuppressive drugs (e.g. Azathioprine, Cyclosporin)

• Analgesics (painkillers) either by tablet or local anaesthetic creams or gels applied directly to painful fissures.

• Infliximab. This may allow many fistulas to close up. However, closure of the end of a fistula does not necessarily mean the internal tract has been eradicated. Many surgeons fear that abscesses may arise if drainage of the tract is prevented by closure of the opening. Further reseach continues.

2. Nutrition

Dietary improvements may help the healing process, such as:

• high calorie, high protein diet
• low fibre
• vitamin and mineral supplements

3. Rest

Resting may help conserve energy and aid the healing process. It may also ease the pain particularly of abscesses which may cause more pressure pain on standing or walking about frequently.

4. Incontinence

Faecal incontinence may occur due to:

• incompetent anal sphincter as a result of previous surgery
• loose stool
• age and poor control

This may be managed by administration of bulking agents, such as Fybogel, Normacol, Celevac and an anti-diarrhoeal agent, such as Loperamide. These agents tend to be more effective when used together.

The formation of a 'plug', made out of toilet paper and inserted just inside the anus, may prevent soiling of the underwear.

Various sized pads, to wear inside underpants, are also commercially available.

5. Hygiene

Diarrhoea and leakage from the anus may cause soreness and irritation. Frequent warm baths, perianal showers or the use of a bidet, particularly after having bowel movements, should be performed.

Plain, moist tissue wipes are more gentle and less abrasive than toilet tissue.

Following bathing, gently patting the perineum with a towel, or use of the ‘cold shot’ setting on a hair dryer will be less traumatic to the tissue.

Conservative Surgical Management

Surgical treatment of perianal disease is usually performed if symptoms persist despite medical treatment. This is due to the poor healing rates and risks of incontinence associated with surgical treatment. However, it may be necessary to treat abscesses or fistulae surgically.

Abscesses may require incision and drainage if there is pain and inflammation caused by pus under pressure.

Fistulae may require incision and drainage either with a small tube or a draining seton (a small stitch) which holds the tract open allowing it to drain. These may be left in for several weeks or months.

Many studies show that the degree of rectal involvement in Crohn's disease has an influence on the success rate of surgical management. The greater the inflammation, the poorer the response.

Rectal strictures are often associated with long-standing disease and periodic dilation may help. This may be continued manually with an anal dilator in varying sizes.

Faecal diversion, i.e. colostomy or ileostomy. This remains a controversial procedure but may allow healing of perianal infection in severe disease although relief may only be temporary. If chronic ill health and incontinence have caused major inconveniences to daily living, this option may provide a better quality of life.