An anal fissure is a split in the lining of the anus, the fissure is described as acute if it has been present for less than six weeks, or chronic if present for longer. Once a fissure develops, the internal anal sphincter tends to spasm, causing further separation of the split, impairing healing and causing pain.

Anal Fissure Symptoms

Patients with an anal fissure may first note bleeding and pain with bowel movement. Once a fissure develops, these symptoms can occur after every bowel movement; the pain can last several minutes to hours. Bleeding is usually mild and limited to a small amount on toilet paper or the surface of stool. As the fissure becomes chronic, pain and bleeding may be intermittent, some patients also note itching or irritation of the skin around the anus.

Causes and Risk Factors

Anal fissures are usually caused by trauma that stretches the anal canal;

• Passage of large or hard-constipated stools or explosive diarrhoea.
• Following childbirth
• Anal fissures can also occur in patients who have other medical conditions such as Crohn's disease (an inflammatory disease of the intestines).

Diagnosis

Anal fissures can usually be diagnosed based on the symptoms described above and a physical examination. These examinations can cause increased pain. A rectal examination or anoscopy (insertion of a small instrument to view the anal canal) can often be avoided in the initial diagnosis of a fissure.

Treatment for Anal Fissure

The goal of treatment for anal fissures is to relieve the pain and spasm and heal the fissure. People who have a new anal fissure may heal on their own without special treatment. By contrast, those with a chronic anal fissure usually require additional therapy. Initial treatment is aimed at eliminating constipation, softening stools and reducing anal sphincter spasm. There are several approaches to reducing anal sphincter spasm, which will be described below. These measures are successful in 60% to 90% of patients. However, some patients may not heal or develop frequent recurrences. Such patients may require surgery, which is successful more than 95% of the time.

Fibre therapy

Avoiding hard bowel movements will prevent over-distension of the anus, which could open a healing fissure. Increasing fibre in the diet is one of the best ways to soften and bulk the stool. Fibre is found in fruits and vegetables. The recommended amount of dietary fibre is 20 to 35 g/day. Fibre supplements are commercially available, including psyllium seed (Metamucil®), wheat dextran (Benefiber®), and calcium polycarbophil (Fibrecon®). These products work by absorbing water and increasing stool bulk. They may be used alone or in combination with dietary changes, and are safe to use every day.

Laxatives

A variety of drugs and natural products are available for treating constipation. People are often concerned about the regular use of laxatives, fearing that they will become dependent on them. A gentle laxative is Macrogol (brand names movicol,osmolax,clearlax) this works by retaining fluid in the large bowel to soften the stool and is safe to use longer term.

Sitz baths 

During Sitz baths, the rectal area is immersed in warm water for approximately 10 to 15 minutes two to three times daily. It is also possible to use a bathtub as a sitz bath by simply filling it with 2 to 3 inches of warm water. Additives such as soap and bubble bath are not recommended, you can add some salt to the water. Sitz baths work by improving blood flow and relaxing the internal anal sphincter. Alternatively showering especially with hand held showers is adequate.

Topical Ointments

Rectogesic is a topical ointment that works by reducing the internal anal sphincter pressure and increasing blood flow to the injured tissue decreasing pain and further facilitating healing. It is important to use this as per the instructions on the pack.

Surgery 

Surgical procedures are generally reserved for people with anal fissure who have tried medical therapy for at least one to three months and have not healed. There are 2 common procedures;

• Lateral sphincterotomy - which relaxes the internal anal sphincter by cutting a small nick into the internal anal sphincter, allowing the fissure to heal.
• Fissurectomy with flap repair – the scar tissue of the fissure is excised and a flap of healthy tissue from the anal lining is attached to promote healing of the fissure.

This is performed under general anaesthesia often as day surgery; post-operative pain is usually mild and is often less than the pain of the fissure itself. Patients usually return to normal activity within one week. Some minor leakage can occur in up to 45% of patients in the immediate surgical recovery period.

The risk of incontinence is predominately associated with lateral sphincterotomy. Dr Meade treats the majority of anal fissures with fissurectomy / flap repair.

Post-op care

• On discharge, you will be prescribed regular panadol for pain and a stronger analgesic to be taken only as needed.
• Benefiber (soluble fiber supplement) to prevent constipation
• Osmolax (laxative) as needed to get bowels moving
• Sitz baths or showers after bowel motions, more frequent if desired (heat helps to relax the anal sphincter and relieve pain after bowel motions
• Patients are usually comfortable within 1-2 weeks; you may have some slight bleeding with bowel motions.