Sally Wright has worked as a Stoma Care Nurse for over 15 years, providing specialist care, education, and support to individuals recovering from stoma surgery within the community. Sally recognises that every patient’s recovery journey is unique, and she has a particular interest in the psychological aspects of adapting to life with a stoma. Her previous role as a Dermatology Sister highlighted the importance of emotional wellbeing whilst coming to terms with changes to our bodies and the impact on self esteem.
First things first, what is a fistula?
So, what is a fistula? A fistula is an abnormal passage or tunnel that forms between two parts of the body that would not normally be connected.
There are two main types of fistulas:
- Internal fistulas form between two organs, such as different parts of the bowel.
- External fistulas, sometimes referred to as skin fistulas, form between an internal organ and the surface of the skin.
Fistulas usually develop after surgery or injury, but they can also be caused by infection or inflammation. Although they can sound worrying, many fistulas can be successfully managed and treated.
Gastro-intestinal fistulas are most commonly seen after abdominal surgery or in people living with long-term digestive conditions. If you've had stoma surgery, it's worth speaking to your doctor about your individual risk, the symptoms to watch for, and whether your stoma care nurse should monitor any changes.
One of the biggest challenges with a fistula is managing its output. Digestive fluids can be acidic, so protecting the surrounding skin is an important part of ongoing care.
What is fistulation?
Fistulation is the process of a fistula forming. It happens when inflammation or infection damages tissue, allowing an abnormal tunnel to develop between organs or between an organ and the skin.
In the bowel, fistulation often begins when inflammation causes ulcers to form in the lining of the intestine. These ulcers can gradually extend through the full thickness of the bowel wall, creating a passageway that allows fluid or infection to drain. An abscess, which is a collection of pus, can also lead to fistulation.
What causes a fistula?
Most fistulas in the bowel develop after abdominal surgery, especially surgery involving the intestines or a stoma. However, they can also occur because of ongoing inflammation or other medical conditions.
You may be more likely to develop a fistula if you have:
- Abdominal surgery
- Stoma surgery
- Inflammatory bowel disease, such as Crohn's disease
- Ulcers
- Pancreatitis
- Cancer
- Radiation treatment to the abdomen
- Abdominal trauma, such as a stab wound
Types of fistulas associated with a stoma
Now, not all fistulas develop unexpectedly. Some are created deliberately during surgery, while others form as a complication afterwards.
The two main types of stoma fistulas are:
- Mucous fistula
- Gastro-intestinal fistula
What is a mucous fistula?
A mucous fistula is intentionally created by a surgeon during some bowel operations.
When part of the bowel is removed and a stoma is formed, the disconnected section of bowel continues to produce mucus and gas. A mucous fistula allows this mucus and gas to leave the body safely, where it can be collected in a stoma bag.
This results in two stomas, known as a distal mucous fistula.
If you have a loop ileostomy or loop colostomy, a separate mucous fistula is not usually needed because one opening of the loop passes stool while the other allows mucus to drain naturally.
What is a gastro-intestinal fistula?
A gastro-intestinal fistula is an abnormal opening that develops in the stomach or intestines.
Instead of remaining within the digestive tract, fluids from the stomach or bowel leak through the opening. These fluids may pass into another organ or travel through the skin to the outside of the body.
Because digestive fluids contain enzymes and bacteria, this type of fistula can lead to:
- Infection
- Dehydration
- Malnutrition
- Poor absorption of nutrients
Spontaneous gastro-intestinal fistulas account for around 10–15% of cases (Source). They are often linked to inflammatory bowel disease, bowel infections such as diverticulitis, or malignant tumours.
Crohn's disease is one of the most common causes. Around 40% of people with Crohn's disease develop a fistula at some point during their lifetime (Source).
Symptoms of a fistula
The symptoms of a fistula depend on where the fistula is located.
External or skin fistulas
External or skin fistulas often cause fluid to drain through an opening in the skin. Other symptoms may include:
- Abdominal pain
- Painful bowel obstruction
- Fever
- Raised white blood cell count
Internal fistulas
People with internal fistulas may experience:
- Diarrhoea
- Rectal bleeding
- Bloodstream infection (sepsis)
- Poor absorption of nutrients
- Weight loss
- Dehydration
- Worsening symptoms of the underlying condition
How are fistulas treated?
Doctors aim to treat most fistulas without surgery, as most will close naturally within approximately five weeks of treatment.
Treatment focuses on supporting healing, maintaining good nutrition and preventing infection.
Depending on the cause and severity, treatment may include:
- Antibiotics
- Immune-suppressing medicines if Crohn's disease is the cause
- Surgery to remove the fistula and part of the bowel if it does not heal
- Nutrition given through a vein while the fistula heals in some cases
If you have a stoma, your stoma care nurse will advise you on the best way to manage your fistula. Depending on the amount of output, this may involve using a small stoma bag or a dressing.
Protecting the surrounding skin is an important part of treatment. Barrier sprays and barrier wipes are often recommended to help protect the skin from acidic digestive fluids and reduce soreness.
If you notice new symptoms or think you may have developed a fistula, contact your healthcare team or stoma care nurse for advice.
FAQ: What is a fistula
What is the main cause of a fistula?
The most common cause of a fistula is abdominal surgery, including stoma surgery. Fistulas can also develop because of inflammatory bowel disease such as Crohn's disease, infection, abscesses, injury, ulcers, cancer or radiation treatment.
What happens if you have a fistula?
What happens depends on the type of fistula. Some fistulas cause digestive fluid to leak into nearby organs or through the skin, which can lead to infection, dehydration or poor nutrient absorption. Others, such as a mucous fistula, are created during surgery to allow mucus and gas to leave the disconnected section of bowel safely.
What does a fistula look like?
An external or skin fistula may appear as a small opening in the skin that leaks fluid. Internal fistulas cannot usually be seen from the outside and are more likely to cause symptoms such as diarrhoea, abdominal pain or weight loss.
Do fistulas ever go away?
Yes. Many fistulas heal without surgery. Most fistulas that produce a small amount of fluid will close on their own with appropriate treatment and support. Others may require medication, nutritional support or surgery if they do not heal naturally.