ANAL FISTULA

This is a very common condition affecting the rectum and anus. A patient with this condition first feels discomfort and pain around the back passage. Patients may also complain of feeling ill with chills and fever. They also notice a lump around the anus 

What is an anal abscess?

An anal abscess is an infected cavity filled with pus found near the anus or rectum. 

What is an anal fistula?

An anal fistula, usually the result of a previous abscess, is a small tunnel connecting the anal gland from which the abscess arose to the skin of the buttocks outside the anus. 

What causes an anal abscess? 

An anal abscess results from an acute infection of a small gland just inside the anus, when bacteria or foreign matter enters the tissue through the gland. 

What causes a fistula?

After an abscess has been drained surgically, a tunnel or passage may persist connecting the anal gland from which the abscess occurred to the skin. If this occurs, continued drainage from the outside opening may indicate the persistence of this tunnel. If the outside opening of the tunnel on the skin surface heals, recurrent abscess may develop. 

What are the symptoms of an abscess or fistula?

Symptoms of both conditions include constant pain, sometimes accompanied by swelling. Other symptoms include irritation of skin around the anus, drainage of pus (which often relieves the pain), fever, and feeling unwell in general. 

Does an abscess always become a fistula? 

No. A fistula develops in about half (50%) of all abscess cases, and currently we are unable to predict the outcome.

How is an abscess treated?

An abscess should always be treated by draining the pus from the infected cavity. This is done by making a cut on the swelling of the abscess on the skin near the anus to relieve the pressure. Small abscesses can be drained under local anesthetic in the doctor’s clinic but larger abscess and patients who have other significant medical conditions such s diabetes should be admitted to hospital for treatment. Antibiotics are not usually an alternative to draining the pus, because antibiotics are carried by the blood stream and do not penetrate the fluid within an abscess. 

What investigations are needed for suspected anal fistula?

No investigations are required for simple anal fistulas. Complex fistulas can be confirmed and clearly demonstrated with MRI scans. Your coloproctologist will examine you and make the decision regarding scans

What is the treatment for an anal fistula? 

Surgery is always required to treat an anal fistula. It is very important that patients find a surgeon preferably a colorectal surgeon/coloproctologist who has experience with managing anal fistula and the complications arising from it. The reason is that fistula tracks can pass through muscles which control continence and any damage to these muscles will result in varying degrees of anal incontinence. Surgery for fistula if identified can be done at the same time of drainage of abscess. This requires relevant expertise in colorectal surgery. Fistulae often develop two to three months after an abscess is drained. Fistula surgery usually involves cutting a small portion of the anal sphincter muscle to open the tunnel, joining the external and internal opening and converting the tunnel into a groove that will then heal from within outward. Most of the time, fistula surgery can be performed as day surgery procedure or on a short hospital stay.

How long does it take before patients feel better? 

Pain after fistula surgery is usually mild to moderate in the first few days after the operation and can be controlled with tablets that relieve pain. The amount of time lost from work or school is usually minimal. Treatment of an abscess or fistula is followed by a period of time at home, when soaking the affected area in warm water (sitz bath) is recommended three or four times a day. Stool softeners may also be recommended. It may be necessary to wear a gauze pad or mini-pad to prevent the drainage from soiling clothes. Bowel movements will not affect healing. 

Will an abscess or fistula reoccur?

With expert treatment the problem usually does not recur.