Anorectal Abscess-Fistula


Anorectal Abscess and Fistula

What is an anorectal Abscess?

An abscess is simply a localized infection containing pus. When they occur around the anus, they are often referred to as perirectal or perianal abscesses. They can occur anywhere around the anus.

How do you get an perirectal abscess?

Most abscesses around the anus  result from infection of a small glands around the anus. These glands help to secret mucous and lubricate the anal canal. They are similar to salivary glands in the mouth.

The typical symptoms of an abscess are pain, redness and swelling. The pain is often excruciating and constant . Sometimes people have fever and chills, if the abscess is large enough.

The treatment for an abscess around the anus is drainage. Sometimes the abscess will drain spontaneously through the skin, but most times it will require surgical drainage by a physician. This is done by "freezing" the area with local anesthetic and cutting into the abscess cavity. When an abscess is drained, many people notice relief immediately and there is usually dramatic improvement within 12 hours.

Unfortunately, after the abscess is drained, a significant number of people (30-50% will develop a persistent connection from the anal gland to the skin. This is called an Anal Fistula (Fistula-in-Ano).


What to do if I have drained an abscess around your anus?

There are 5

  1. 1. If I have put packing into the wound, you should remove it later the same day or next morning. Often it is stuck in and adherent and the best way to remove the packing is to soak in a warm bath for 10-15 minutes. You should be able to gently ease it out. Don’t worry if it bleeds a little bit.

  2. 2.Take regular sitz-baths 3-4 times daily and after any bowel movement. A sitz bath is simply soaking your behind in warm for 10-15 minutes.  Plain water is fine. If you like, you may use epsom salts, but they are not necessary. Do not use bubble bath or other chemicals, though. The sitz-bath helps to keep the area clean and rinses debris out. Alternatively, you can also shower and let warm water gently run over your buttocks and the affected area. But I think a bath works best.

  3. 3.Dress the wound with a simple piece of cause. Often a feminine pad works well, especially if there is a lot of drainage. You do not need to pack things into the wound. It will drain naturally, if the drainage opening is adequate.

  4. 4.Takes lots of fibre and use a fibre supplement like metamucil, Benefiber etc.   One tablespoon daily works well. These are not laxatives, but simply fibre supplements and they will help maintain bowel regularity

  5. 5.Control pain with simple medications like Acetaminophen (Tylenol) or Ibuprofen (Advil, Motrin). Try to avoid Tylenol #3 if possible, as it contains codeine and will tend to make you constipated.

What is an Anal Fistula?

An anal fistula is an abnormal connection between the anal canal and the skin outside the anus.  See Diagram BelowThey are very common and are almost always the result of an abscess described above.

They usually become obvious within a few months of having an abscess, but sometimes only show up a year or so later. They often manifest with more subtle findings, such as mild discomfort, persistent drainage, foul odor or simply a firm lump around the anus. For some patients the diagnosis of a fistula only becomes apparent after they develop another abscess in the same location as the first one.


How do you treat an anal fistula?

The treatment of fistulas is much more complicated than for an abscess. They do not resolve on their own and will generally cause problems for many years unless dealt with surgically.

Surgery usually involves day surgery with a short general anesthetic to explore the fistula tract. We try to identify the internal opening inside the anus and connect it with the external opening. When we have done that, the fistula tract needs to be opened up along its entire length, cleaned out and allowed to heal

The Trouble with Fistulae

The problem with opening the fistula tract is that it often goes through part of the sphincter muscle and opening the tract may involve cutting some of this muscle around the anus. A person can have some of the muscle of the anal sphincters cut without much trouble, but if too much of the muscle is cut, then there is a risk a patient may develop trouble with control around the anus. This usually means difficulty controlling gas, but sometimes if too much of the sphincter has been cut, it can mean trouble with controlling stool. The term to describe this problem is fecal incontinence.

Rest assured that it is the highest priority of every surgeon who operates on fistulas to make sure that nothing is done which will injure the anal sphincter and cause someone to have control problems. For this reason, every fistula requires individual assessment at the time of surgery. If the tract of the fistula is felt to be quite shallow and not involve much muscle, then it can almost always be opened up without risk and allowed to heal. If, however, there is any concern about whether there is perhaps too much muscle involved, then surgeons have a number of tricks they can employ to cure a fistula.

Frequently, this may involve leaving a small suture in place, called a ‘Seton’. A Seton may be made of silk or rubber and serves various purposes. It ensures drainage of the fistula, so another abscess does not reform and it helps make the fistula more shallow and easier to cure.  Setons are frequently left in for a few months, after which time they fall out spontaneously or another operation is required.

How long will it take to cure my Fistula?

All patients need to be aware that Anal fistulae can be complex and it may take 2-4 small procedures over a period of 3-9 months in order to get them to heal completely. We always err on the side of caution and minimizing the risk of significant injury to the anal sphincter. These procedures are usually day procedures and patients come into hospital in the morning and go home a few hours after the surgery

What if there is a lot of muscle involved in my Fistula?

We have a series of other techniques for dealing with complex fistulae. These include use of something called a “fistula plug”,  “anal advancement flap” and others. We will discuss with each patient if we think one of these techniques is necessary.