Tiny glands inside the anus can become blocked and infected, resulting in an abscess. A fistula forms when an abnormal connection or tunnel connects the abscessed gland to the skin surrounding the anus. Pain is a significant symptom of an anal abscess or fistula and it may come and go periodically throughout the day. Other symptoms of an abscess or fistula may include bleeding with or without a bowel movement, bloody drainage, swelling around the anus, fatigue, fever and chills. Small abscesses can typically be treated in a doctor’s office under local anesthesia. Larger abscesses and those that have developed into a fistula may require further treatment. Common treatments include antibiotics, drainage and fistula repair.