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MBChB PhD FRCS

FAQs

Consultant Laparoscopic Colorectal and General Surgeon

Laparoscopic colorectal surgery

Surgery for anal fissures and anal fistulae

Prompt treatment for anal problems is essential

“Both an anal fissure and an anal fistula need to be assessed promptly. Many people feel embarrassed about anal problems, but nurses, physicians and surgeons view the anus as just another part of the human body. While an anal fissure can heal spontaneously, it may not and early treatment can mean avoiding surgery. An anal fistula rarely heals on its own, so the sooner you get help, the sooner you can be fit again.”

Mr Jonathan Wilson is one of the few UK cororectal surgeons to offer minimally invasive surgery to repair anal fissures and anal fistulae.

Colorectal surgeons deal with many different conditions that affect the anus. Haemorrhoids are the most common but anal fissures and anal fistulae are not infrequent. Both problems can affect anyone, sometimes out of the blue, or there may be a predisposing problem such as inflammatory bowel disease (Crohn’s disease or ulcerative colitis).

What causes an anal fissure?

An anal fissure is a small painful tear in the delicate lining of the anal canal. Several factors can lead to tears, but the most common causes are chronic constipation with repeated straining and pregnancy and childbirth. Less commonly, anal fissures can also be linked with inflammatory bowel disease conditions. Rare causes also include sexually transmitted infections in the skin around the anus.

Symptoms of an anal fissure

  • Anal pain on opening the bowels: this can be severe and can last a couple of hours
  • Bright red blood just after passing a stool
  • Irritation and soreness in the anus
  • A small skin tag on the anus, known as a sentinel pile

Treatment of anal fissures

When is surgery needed?

When non-surgical conservative techniques have failed, surgery may be recommended. This is the case in approximately 30 to 40 % of patients with anal fissures.

Most anal fissures will either get better on their own or respond well to medical treatments to relax the anal sphincter. A two-month course of prescription relaxant cream applied to the anus along with laxatives will cure approximately two-thirds of patients. If this is unsuccessful, a day case general anaesthetic may be suggested for injection of BOTOX® into the anal sphincter in an attempt to further relax the sphincter.

Types of surgery available for anal fissures

  • Chemical spinceterotomyNot strictly speaking surgery, this is a new treatment that involves using BOTOX® injections to relax the anal sphincter muscle; it seems promising but its effectiveness compared to traditional surgery is still under review.
  • Anal advancement flap can be performed when all other options have been unsuccessful.
  • Lateral internal sphincterotomy, which is the most commonly performed operation for anal fissures. This is a relatively minor procedure but is still done under general anaesthetic. The surgeon makes a small cut into the internal anal sphincter, the band of muscle that usually holds the anus closed. This releases pressure on the tear, so that it can heal over the next couple of months. This operation is performed as a last resort because surgeons are very worried about weakening the sphincter and causing mild incontinence. However, it is effective at healing anal fissures in over 90% of cases.

What is an anal fistula?

Whereas an anal fissure is a relatively simple tear, an anal fistula is a channel that appears as a hole in the skin beside the anus, but then leads back into the bowel. These channels involve the sphincter muscle of the anus which is responsible for bowel continence. The more the sphincter is involved in the fistula, the more complicated the treatment becomes.

Causes of anal fistulae

Other causes of anal fistulae

Sexually transmitted infections in the skin around the anus may also lead to anal fistulae, including HIV, chlamydia and syphilis. Anal fistulae may also complicate inflammatory bowel disease such as Crohn’s disease and ulcerative colitis. Anal fistulae are also a problem in developing countries, where they are common in women who have given birth without medical help.

The majority of anal fistulae are caused by an infection that causes an abscess, which then bursts on the skin beside the anus. When the abscess wound fails to heal properly, an open channel is created between the skin and the bowel.

Surgical treatment of an anal fistula

Surgery to treat an anal fistula requires a skilled colorectal surgeon. Not only is it difficult to treat the fistula so that it heals well, but it is also important not to damage the anal sphincter or the inside of the anus during surgery as faecal incontinence could then develop.

Types of surgery available for anal fistulae

  • Fistulotomy: this type of surgery is used in nine out of ten cases of anal fistula. It involves making a cut along the line of the fistula, creating an open wound which then heals naturally over one to two months. This is the most successful surgical technique with a success rate over 90 %.
  • Use of a loose seton: if the fistula involves too much of your anal sphincter muscle, then it is unwise to perform lay-open surgery without causing damage and incontinence. An alternative method is to introduce a surgical thread (seton), which is left inside the channel. The thread is soft and comfortable and can be felt immediately beside the anus. This allows better drainage of the fistula, thereby improving symptoms. This can be a temporary or permanent treatment.
  • Fistulectomy followed by an advancement flap: the entire fistula is cut away and a piece of tissue from the rectum or skin from near to the anus is used as a type of graft to cover the exposed tissue, allowing it to heal.