ANAL ABSCESS AND FISTULA
An anal abscess is an infected cavity filled with pus near the anus or rectum.
An anal fistula (also called fistula-in-ano) is a small tunnel that tracks from an opening inside the anal canal to an outside opening in the skin near the anus. An anal fistula often results from a previous or current anal abscess.
Small glands just inside the anus become clogged with bacteria, faeces or foreign matter, this may result in an infection and abscess. Crohn’s disease, cancer, trauma and radiation can increase the risk of infections and fistulas.
A patient with an abscess may have pain, redness or swelling in the area around the anus. Other common signs include feeling ill or tired, fever and chills. Patients with fistulas have similar symptoms, as well as drainage from an opening near the anus.
Most anal abscesses or fistulas are diagnosed and managed based on clinical findings. Occasionally, imaging studies such as ultrasound or MRI can help in the diagnosis and management of deeper abscesses and the fistula tunnel.
The treatment of an abscess is surgical drainage under most circumstances. For most patients, an abscess can be drained surgically through a simple procedure. An incision is made in the skin near the anus to drain the infection.
Surgery is nearly always needed to treat an anal fistula. In many patients, if the fistula is not too deep, a fistulotomy is performed. During this surgery, the fistula track will be opened to allow healing from the bottom up.
If the fistula track does involves a large portion of the sphincter muscle, other more complex surgeries are done to treat the fistula without harming the sphincter muscle. More difficult cases may require multiple surgeries.
Antibiotics alone are not effective in treating abscesses or fistula. With an accurate medical history and undergoing a physical exam are important steps in deciding if antibiotics are required.