1.What is a perianal abscess?
A perianal abscess is an infected cavity filled with pus that is found near the anus or rectum.
2.What is an anal fistula?
An anal fistula is often the result of the development of a previous or current perianal abscess, and up to 50% of patients with a perianal abscess will develop an anal fistula. In the normal anatomy of the body, there are small glands in the anus, and sometimes these glands may become infected due to blockage, leading to an abscess. An anal fistula is a duct under the skin that connects an infected gland to an abscess. An anal fistula may or may not be accompanied by an abscess and opens in the skin of the buttocks near the anus. Other conditions that may lead to an anal fistula include Crohn’s disease, radiation therapy, trauma, and malignancy.
3. How do I get a perianal abscess or anal fistula?
An abscess is the most common result of an acute infection of the anal glands. Occasional blockage of the anal glands by bacteria, fecal material or foreign bodies creates the conditions for the formation of an abscess cavity. Other pathological conditions make these infections more likely to occur.
A fistula connecting the infected anal gland to the external skin may persist after the abscess has collapsed on its own or been incised. This usually requires some kind of external drainage and occurs in up to 50% of (perianal) abscesses. When a fistula is present, the abscess can recur if the opening in the skin heals.
4. What are the signs and symptoms of an abscess or fistula?
Patients with abscesses may have pain, redness or swelling in the area near the anus. Fatigue, weakness, and fever or chills are also common. With an anal fistula, irritation from the perianal skin or drainage from the external opening can lead to signs and symptoms similar to those of an abscess.
5. Do I need certain specialized tests to diagnose an abscess or fistula?
Most anal abscesses or fistulas can be diagnosed and treated based on clinical manifestations alone. However, sometimes further tests, such as ultrasound, CT or MRI scan, can help diagnose deeper abscesses or describe the course of the fistula to guide treatment.
6.What is the treatment for perianal abscess?
In most cases, the treatment for abscesses is surgical drainage. An incision is made near the anus to drain the infection. This procedure can be done under local anesthesia in an outpatient setting or under deeper anesthesia in the operating room. Certain patients who are more susceptible to severe infection may require hospitalization, such as diabetics or patients who are immunocompromised.
7.Do I need antibiotics to treat perianal abscess?
The use of antibiotics alone is not a good substitute for drainage surgery. For uncomplicated abscesses that have been drained, additional antibiotics will not shorten the healing time or reduce the likelihood of recurrence. There are some conditions that require antibiotics, such as patients with immune deficiency or impairment, patients with heart valve lesions, or extensive cellulitis. A thorough discussion of previous medical history and physical examination findings is essential in deciding whether to use antibiotics.
8. What is the treatment for anal fistula?
Surgery is almost always required to cure an anal fistula. Surgery can be fairly simple, but it can also be complex and sometimes requires staged or multiple surgeries.
Although sometimes fistulas do not manifest until weeks or even years after the initial drainage, surgery may still be performed at the same time as abscess drainage. In the case of a simple fistula, a fistulotomy may be performed. In this approach, the inner (infected anal gland) fistula and the outer opening are all cut open, creating a “slot” where the wound will heal from the inside out. In a limited number of cases, this procedure requires a small incision of the anal sphincter, which is unlikely to interfere with normal bowel control. Other procedures include the placement of some material inside the fistula to plug the fistula or surgical alteration of the surrounding tissue to close the fistula, depending on the type, length, and location of the fistula. Most surgeries can be performed on an outpatient basis, but sometimes hospitalization may be required.
9. How is post-operative care provided?
Postoperative pain medication may be used to control pain, and fiber and laxatives may be consumed. Patients should schedule local sitz baths at home and avoid constipation related to prescription pain medications. Discuss with your surgeon details of care and preoperative rest time to prepare for postoperative care.
10. Can a perianal abscess or fistula recur?
Both are unlikely to recur if treated adequately and recovered properly. However, both abscesses and fistulas have the potential to recur regardless of whether open surgery or minimally invasive treatment is properly chosen. If you experience similar symptoms as before, it is suggestive of recurrence and you are advised to seek a colorectal surgeon to manage your case.