Symptoms of Fistula

Anal fistula symptoms often follow an earlier painful swelling near the anus that burst or was drained.

Common symptoms

• A small opening on the skin near the anus, which may look like a boil or pimple
• Discharge of pus, blood or sometimes stool-stained fluid from that opening
• Pain or throbbing, often worse when sitting, moving, coughing or passing stool
• Skin irritation, itching or redness around the anus from the discharge
• Swelling that comes and goes
• Foul-smelling discharge
• Fever, chills or feeling unwell when an abscess forms again

Typical pattern

Symptoms often settle when the tunnel drains, then flare again when it blocks. This repeating cycle is a clue that a fistula is present.

Not always a fistula

Piles, fissures, skin infections and some other conditions can look similar. Only an examination can tell them apart.

See a doctor soon if

• Discharge or pain near the anus lasts more than a few days
• A boil near the anus keeps returning
• There is bleeding or passing of stool or gas from the opening

Seek same-day care if

• Severe pain and swelling with fever (a possible abscess)
• Unable to pass stool or urine
• Heavy bleeding or feeling faint

For emergencies, call 112 or 102.

Important

Delay lets infection spread and makes later surgery more complex. Early assessment by a surgeon, ideally a colorectal specialist, is advised.

Fistulas in other places

Fistulas can also occur elsewhere, for example between the bowel and the skin or vagina. Passing gas or stool through the vagina or urine through the rectum needs prompt medical assessment.