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Health Topics

Perirectal abscess: Causes, symptoms and treatment


June 6, 2018

A colorectal surgeon explains this painful, mysterious condition that many people are embarrassed to talk about.


A perirectal abscess is a collection of pus that forms next to the anal canal. It can cause a lot of pain and will most likely require medical attention. While it’s a pretty common problem, few people have heard of it. Here, Alexander Hawkins, M.D., MPH, a colorectal surgeon at Vanderbilt University Medical Center, answers questions about perirectal abscesses and what’s involved with treating them.


What causes a perirectal abscess?

There is an area of the anal canal where the lining of the gut changes to tissue that is more like skin.  This area can have a number of folds, or “crypts,” that can get blocked.  The resulting infection creates pus, which collects in areas around the anal canal.


What are the symptoms of a perirectal abscess?

There are a number of symptoms. These include severe, constant pain in the anal area; fever and/or chills; and feeling sick or tired. Typically the abscess will present as a lump that grows in size the longer the infection goes untreated. Overall, pain is probably the most frequent symptom.


How do you treat a perirectal abscess?

Once a perirectal abscess has grown to a size that becomes painful, the most appropriate treatment is usually surgical drainage. If the abscess is readily apparent, this can be done in the office, the emergency department or at an urgent care clinic. For other, potentially deeper abscesses, patients may need to be taken into surgery to have it drained under anesthesia.


How long does healing take after an abscess has been drained?

There is a lot of variability in healing time. It depends on many things, including the location of the abscess, the size of the abscess and other medical conditions a patient may have. Your doctor can give you more detailed information that’s specific to you.


Sometimes these abscesses come back. Why does that happen?

An abscess can reoccur for two main reasons. First, if the initial abscess is not completely drained and the skin heals over before the pus can completely drain. In this case, another incision and drainage procedure is necessary. Second, sometimes abscesses can be fed from a hole in the anal canal that remains open. In this case, the surgical opening will continue to drain pus and possible stool. We call this an anal fistula. An anal fistula is a tunnel that forms between the anal canal and the area where the abscess appears on the skin.


When would a surgeon perform an exam under anesthesia, and what would the surgeon be looking for?

There are a number of reasons to perform an exam under anesthesia. The surgeon may want to make sure the abscess is completely drained. He or she may also want to see if they can identify a fistula.


If someone thinks they have an abscess, what should they do? Can it be treated over the counter?

You can try a “sitz” bath. This is a shallow, warm bath that helps clean and heal the anal area. Do that twice a day for 30 minutes each bath. If that doesn’t take care of the symptoms, the best thing to do is to reach out to a healthcare provider. This can be your primary care provider, an urgent care practitioner or an emergency room provider. If an abscess has reached a certain size, it is best served by cutting a small hole to drain out the pus.

It’s important to have a primary care provider to oversee all of your healthcare needs. Click here to see the locations and options available for Vanderbilt Primary Care.

Alexander Hawkins, M.D., M.P.H., is assistant professor of surgery in the Division of General Surgery, Colon & Rectal Surgery at Vanderbilt University Medical Center. His clinical and research interests include colorectal cancer, inflammatory bowel disease, diverticulitis, anorectal disease and transanal endoscopic microsurgery.