Anal (or anorectal) abscesses are localized infections, which result in pus collecting and forming a cavity in the rectal area. This condition can occur for a variety of reasons; most commonly from blocked or infected anal glands. Other reasons for abscesses include diseases of the anus or rectum, like Crohn’s disease or anal fissures, or an accidental wound or injury. An anal abscess occurs at a rate of about 8 per 100,000 people and are not influenced by diet, hemorrhoids or hygiene.
Causes of Anal Abscesses
Certain medical conditions and factors can influence the occurrence of an anal abscess. Some causes of anal abscesses include:
- Prior occurrence of anal abscess, fissure, or fistula
- Injury to tissues in the area, such as surgery, or obstetric trauma
- Inflammatory bowel disease, notably Crohn’s disease
- Exposure to radiation
- Sexually transmitted diseases
- Treatment with prednisone, other steroids, or chemotherapy drugs
- Frequency of participation in anal sex
- Diabetes, HIV/AIDS, or other compromises to the immune system
The first person to ask about your risk of anal abscess is your proctologist, since every patient is unique. Even if you do not have any of the medical or lifestyle factors that increase the possibility of anal abscesses, it is still possible for anyone to develop one.
Typically, an anal abscess will present with a noticeable lump at the site, as well as inflammation and pain in the area around the abscess. The site may be painful only when manipulated, or might cause a consistent throbbing. Patients can also experience fatigue, as well as a fever or chills, depending on the advancement of the infection and their body’s condition. In some cases, there may be discharge from the abscess directly or through the rectum; this can cause the area to fluctuate in size and pain level. Keep in mind that not all anal abscesses will be superficially visible; sometimes a deep abscess can create a throbbing pain throughout the rectum and anus or cause a fever with seemingly no immediate explanation.
A physical examination is the first step for your proctologist to take when diagnosing an anal abscess. Along with a clinical examination of the site, he or she may order imaging tests (such as an ultrasound, CT scan) to gather more information about the abscess. These provide information that your proctologist needs prior to surgical or other intervention – information like the depth, severity, shape, and possible origin of the abscess.
Drainage of anal abscesses either in the office or operating room remains the mainstay of therapy for abscesses. In rare instances, some very small infections may respond to antibiotics alone without drainage. However, this an unusual situation. In fact, antibiotics are typically not required at all in the treatment of abscesses because drainage is so effective. Some patients with extensive infection and medical comorbidities (such as diabetes or replaced heart valves) benefit from courses of IV or oral antibiotic following drainage.
Most abscesses can be drained in the office under local anesthetic. A small needle may be used to locate the collection of pus and a scalpel used to make a small incision over the cavity to promote drainage. For larger or deeper abscesses, or ones difficult to find in the office, further tests (such as a CT scan) or a trip to the operating room may be necessary. Patients requiring an operation are given anesthesia and the area drained while they rest comfortably. Most return home later that same day. For some patients with additional health complications, such as diabetes or other causes of weak immune systems, brief hospitalization may be appropriate.
Office drainage of an abscess typically provides immediate relief. Most patients receive a prescription for pain medication and most return to work within a few days. Antibiotics are generally not required. Soaks in warm water and dressing changes may be advised, as are a bowel regimen to soften stools.
After anal abscess surgery, care is similar to office drainage. Typically you will receive medication for pain management, as well as recommendations for your diet in order to prevent constipation — such as fiber along with laxatives or other stool softeners – especially since some pain medications can cause constipation. Depending on your case, you may require some time off work before surgery as well as afterward. You may have a daily or twice daily protocol of sitz baths (sitting in waist-deep warm water to gently soak the surgery site) and/or bandages to replace for a period of time after your surgery.
The outcome and risks of recurrence of abscesses depend on the underlying cause of the infection. While infected glands remain the most common cause of abscesses, many resolve with the treatment of the abscess. Over 50 % of patients have a complete resolution of their infection following adequate drainage. Patients with underlying diseases like Crohn’s disease may require additional medical treatment to optimize outcomes following abscess drainage.
In cases where the anal gland remains an active issue, an abscess recurrence may occur or a fistula (a tunnel between the anal gland and the skin outside the anus) may develop. A fistula typically occurs about 40-50% of the time. It remains quite difficult to predict in whom these will form after abscess drainage. Observation and follow up are the mainstays of diagnosis. Patients with anal fistula typically require surgery to treat the problem.
At Saleeby & Wessels Proctology, we recognize that it’s important for you to be well-informed so that you can have a safe and comfortable patient experience. Our top priority is taking a Patient-First Approach, where we put your needs first and demonstrate respect for you in every part of our practice. If you’re concerned you might have an anal abscess, or have any other proctology questions, give us a call at (919) 636-3803 to arrange an examination with one of our highly qualified proctology specialists.