Fistula

Overview

A fistula (say: FIST-yoo-luh) is a small tunnel that forms where it shouldn't be. It connects two parts of the body that are not normally joined, or connects an organ to the skin. Fistulas can happen in many places. The most common kind seen in general practice is an anal fistula (also called fistula-in-ano). This is a narrow channel between the inside of the back passage (anus) and the skin near it. It usually starts as an infected pocket, called an abscess, that does not heal the normal way and instead makes a small tunnel. Other types include fistulas that form after childbirth (obstetric fistula, linking the birth canal to the bladder or bowel), fistulas between loops of bowel and the skin (after surgery or inflammation), and 'AV fistulas', which are actually created on purpose by surgeons to help with kidney dialysis.

Anal fistulas are fairly common, and surgeons treat them regularly. Obstetric fistulas are now rare in countries with good maternity care, but they still affect many women worldwide who give birth without skilled help. Fistulas related to bowel disease or surgery are less common but well known to doctors.

Anyone can get a fistula, at any age. Anal fistulas are more common in adults, and in people with Crohn's disease or other bowel conditions. In babies, a small fistula near the anus is seen most often in boys under one year old. Obstetric fistulas affect women and girls who have had a long, difficult birth without medical care. People who have had surgery, radiation treatment, or a serious infection in an area are also at higher risk.

Symptoms

Common symptoms

• Pain or throbbing around the back passage, especially when sitting or going to the toilet
• An opening or small hole in the skin near the anus that leaks pus, blood, or watery fluid
• Bowel wind or stool leaking from that opening
• Itching, soreness, or redness of the skin around the area
• A hard lump or swelling near the anus
• Mild fever or feeling generally unwell when there is an infection

Symptoms in children

• A small pimple-like opening near the anus, often in a baby boy under one year old
• Mild redness or a little pus when the nappy is changed
• Fussiness or crying during nappy changes or when passing stool
• Usually very little else - many babies are otherwise well and feeding normally

Symptoms in older adults

• Leaking from the back passage that may be mistaken for poor bowel control
• Ongoing discharge that can irritate and damage the skin
• Symptoms that appear after bowel surgery, diverticular disease, or radiation treatment
• Slower healing and a higher chance of infection, so symptoms may last longer

Causes

Main causes

• An infected gland near the anus that turns into an abscess and then drains through a tunnel instead of healing
• Crohn's disease or another inflammatory bowel condition - inflammation can burrow through tissue
• Surgery, especially in the bowel, bladder, or genital area, where a join can fail to heal
• Childbirth injury - long, obstructed labour can press tissue until a hole forms between the birth canal and the bladder or bowel
• Radiation treatment, which can damage tissue and slow healing
• A tear or injury to the area, or an infection after a procedure
• Some cancers, and the treatments for them

Risk factors

• Crohn's disease or other inflammatory bowel disease
• Diabetes, which slows healing and raises infection risk
• Repeated abscesses or boils near the anus
• Previous surgery or radiation in the pelvic area
• Long or difficult childbirth without skilled maternity care
• Weakened immunity from illness or treatment
• Smoking, which slows healing

When to see a doctor

See a doctor urgently if:

• Pain, swelling, and fever around the anus that is getting worse
• A new opening near the anus that leaks pus, blood, or stool
• Leaking of urine or stool from the vagina, especially after childbirth
• Bleeding from the bottom that is more than a few spots on the paper
• Any sudden change in bowel or bladder control

Book a routine appointment if:

• An itchy, sore, or weeping spot near the anus that keeps coming back
• A small lump that has been there for weeks without settling
• Ongoing discharge that stains your underwear
• Pain when sitting or passing stool that has lasted more than a few days
• Symptoms that return after you have had a fistula treated before

Diagnosis

A doctor will usually start by asking about your symptoms and your health history, then look at the area. They may gently examine the skin near the anus and, if you are comfortable, do a short internal examination with a gloved finger. This is quick and can be a little uncomfortable but should not be painful - tell the doctor if it is. The aim is to find the opening, work out where the tunnel goes, and check for infection. Some fistulas need scans or a short examination under anaesthetic to map them properly, so the right treatment can be planned.

Tests that may be done

• A physical examination of the area, sometimes with a gloved finger inside the back passage
• Proctoscopy - a small tube with a light is used to look inside the back passage
• An examination under anaesthetic, so the doctor can see the full tunnel while you are asleep
• MRI scan - very good at showing the path of a fistula and any deeper pockets of infection
• Ultrasound scan, sometimes with a small probe in the back passage
• A dye test, where a safe coloured liquid is injected to trace the tunnel
• Blood tests to check for infection or inflammation
• Tests for Crohn's disease or other bowel conditions if these are suspected

What to expect at your appointment

Most of the visit is talking and a short examination. You can ask for a chaperone (a staff member to stay in the room) and you can pause at any point. If you need a scan or an examination under anaesthetic, you will be given clear instructions beforehand, including whether to eat or drink. Results usually come back within days to a few weeks, and your doctor should explain what the findings mean and what the next step is.

Treatment

Treatment depends on the type of fistula, where it is, and what is causing it. Some small fistulas, especially in babies, close without any treatment. Others need a procedure to drain infection and to help the tunnel heal. The goal is always to fix the fistula, protect your bowel and bladder control, and help you feel comfortable again.

Self-care at home

• Keep the area clean and dry - wash gently with plain warm water and pat dry, then wash your hands
• Take warm shallow baths (sometimes called sitz baths) for 10 to 15 minutes a few times a day, which can ease pain and keep the area clean
• Wear loose cotton underwear and avoid tight clothing
• Use soft, unscented toilet paper or a bidet bottle of warm water after a bowel movement
• Change dressings or pads regularly if there is discharge, and use a barrier cream to protect the skin
• Eat plenty of fibre and drink enough fluid to keep stools soft and easy to pass
• Avoid straining on the toilet, and do not squeeze or press on a lump - this can spread infection
• Take simple pain relief as advised by your pharmacist, and follow any instructions your doctor gives you

Medical treatments

Doctors may first treat an infection with a course of antibiotics and drain any pus that has built up - draining is often what gives the most relief. Some fistulas are treated with small devices placed inside the tunnel to help it close, or with a special stitch (called a seton) that keeps the tunnel open so it can drain and settle before a final repair. Other options include plugging or sealing the tunnel, or treatments that encourage healing by removing the lining of the tunnel. Which approach suits you depends on where the tunnel runs and how much of the anal muscle it involves, because protecting your bowel control is always a top priority. If a condition like Crohn's disease is behind the fistula, treating that condition is an important part of the plan.

When is surgery considered?

Surgery is a common and often definitive treatment for anal fistulas. The most straightforward operation opens the tunnel so it can heal from the inside out. Other operations move healthy tissue over the tunnel or reroute it to protect the muscle. Surgery is also used for fistulas caused by childbirth or surgery, and for fistulas that keep coming back. Your surgeon should explain the benefits and the risks, including any effect on bowel control, before you decide.

Living with this condition

Living with a fistula can be practical as well as emotional. Keep spare underwear and pads with you, and plan toilet stops when you are out. A small pad or dressing can protect your clothes. Shower rather than bathe if discharge is heavy, and dry the skin well. Tell your employer, school, or gym only if you want to - you are not obliged to share your diagnosis. Keep follow-up appointments, and write down questions before each visit so you do not forget them.

Lifestyle tips

• Build a routine around meals and toileting to avoid rushing
• Carry a small kit with wipes, a pad, and a change of underwear
• Choose loose, breathable clothing, especially on long days out
• Avoid heavy lifting and straining until your doctor says it is safe
• Stop smoking if you can - it genuinely helps healing
• Keep moving with gentle activity such as walking, which helps your bowel stay regular

Diet and exercise

Eating well can make a real difference. Aim for plenty of fibre from fruit, vegetables, wholegrains, and beans, and drink enough water so your stool stays soft and easy to pass. If fibre makes you bloated, increase it slowly. Some people find spicy food, alcohol, or caffeine makes irritation worse - notice your own pattern rather than cutting things out by default. Gentle exercise like walking or swimming is fine and helps your bowel work well. Avoid heavy weights or hard cycling until your doctor says the area has healed.

Mental health and emotional wellbeing

Fistulas can be embarrassing and isolating, and it is very normal to feel anxious, low, or worried about leaks, smell, or intimacy. These feelings are valid and worth talking about. Tell your doctor how this is affecting you - support is part of your care, not an afterthought. If you ever feel hopeless or have thoughts of harming yourself, contact your local crisis line or emergency services right away. You deserve help quickly, and you are not alone.

Prevention

Not every fistula can be prevented, but some can. Getting an infected or painful lump near the anus checked and treated early is one of the most important steps, because an untreated abscess is the usual starting point for an anal fistula. If you have Crohn's disease or another bowel condition, keeping it well controlled lowers your risk. Good hygiene, staying hydrated, avoiding constipation, and not smoking all help your body heal. For obstetric fistula, skilled maternity care and timely help during a long labour are the strongest protection - if you are in labour and it is lasting a very long time, seek medical help immediately.

Screening programmes

There is no general screening test for fistula. Instead, doctors look for fistulas in people with warning signs, such as ongoing discharge near the anus, leaking after childbirth, or a long-standing bowel condition. If you have Crohn's disease, regular check-ups with your specialist are a good chance to raise any new symptoms early.

Complications

If left untreated

• Infection can spread into nearby tissue and, rarely, into the bloodstream, which is serious
• Ongoing leakage of pus or stool, which irritates skin and can cause painful sores
• The tunnel can branch into new channels, making treatment harder later
• Scarring can narrow the back passage and make passing stool difficult
• Some fistulas can affect bowel or bladder control
• Obstetric fistulas left untreated can lead to kidney damage and lasting nerve injury
• Social isolation, shame, and low mood, which are real health problems in their own right

Long-term outlook

The outlook is generally good. Most fistulas can be treated successfully, and many people are cured after one procedure. Some need more than one step, and some come back, but doctors have a range of options and can usually find an approach that works. Small fistulas in babies often close by themselves. Healing takes time - weeks rather than days - and it is reasonable to expect gradual improvement with the right care and follow-up.

Find support

External links open third-party websites. Ruqelo Health is not responsible for external content. Listing an organisation does not imply endorsement.