Signs, treatment and causes of perirectal abscesses and fistula - Houston Colon – Division of Colon and Rectal Surgery

Signs, treatment and causes of perirectal abscesses and fistula

February 16, 2011

Perirectal abscess is an abscess of pus that is caused by inflammation of soft tissue outside the anal verge. Sometimes, the inflammation creates a fistula that communicates with the rectum too. While both men and women suffer from the condition, men have a three time higher chance of contracting the infection than women.


These Houston anal fissures start  with an abrasion in the lining of the rectum, anal canal or perianal skin which gets infected by Escherichia coli, streptococci or staphylococci. Sometimes an anal tear may arise from injections for treating internal hemorrhoids, wounds from ingested eggshells or fish bones or the insertion of foreign things.

Existing lesions from infected anal fissures, ruptured anal hematoma, prolapsed internal hemorrhoids and lesions in the pelvis like acute appendicitis and diverticulitis can also lead to perianal abscess and fistula. However most of the time, fistula and abscess perirectal develop even though there are no preexisting lesions.

Signs and symptoms

Throbbing pain and tenderness at the abscess site, along with painful swelling are common symptoms of perirectal abscess and fistula. Usually a hard and painful lump also develops on one side of the anal opening, making it difficult to even sit.


The fistula’s opening looks like a pink or red, elevated ulcer located on the skin near the anus. Some patients may also suffer from fever, nausea, vomiting and malaise while the internal opening of the fistula may get palpated as an ulcer.

The Houston colon doctor carries an examination under anesthesia to identify the internal openings of the fistula. In addition to this, the Houston colon doctor performs barium studies, colonoscopy and flexible sigmoidoscopy to rule out all other conditions.


perirectal abscess and fistula is treated by making a surgical incision to discharge pus. The Houston colon doctor will perform an examination to identify a fistula tract, wherein a fistulotomy is performed later on under general, caudal or spinal anesthesia. In case of epithelialized fistula tracts, the doctor may perform fistulectomy to remove the tistulous tract and insert drains that are removed over time.