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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.

What causes anal abscess?

A blocked anal gland, a sexually transmitted infection (STI), or an infected anal fissure can cause anal abscesses. Some other risk factors include: Crohn’s disease or ulcerative colitis, which are inflammatory bowel diseases that cause the body to attack healthy tissue.

What will happen if a fistula is left untreated?

Fistulas can cause a lot of discomfort, and if left untreated, may cause serious complications. Some fistulas can cause a bacteria infection, which may result in sepsis, a dangerous condition that can lead to low blood pressure, organ damage or even death.