A fistula occurs when two organs or structures within the body form an abnormal connection. Fistulas can begin in various ways, but many start as an abscess. Abscesses are pus-filled pockets of tissue. Gradually, the abscess may fill with a bodily fluid such as urine. After a while, the abscess invades another structure in the body. This connects the two structures and forms a fistula. You can think of it as a tunnel that should not be there. Fistulas are most common in the abdomen but can occur anywhere in the body.

Common Types of Fistulas

Four types of fistulas are the most common. Enterocutaneous fistulas connect the small intestine to the skin. They often result from surgical complications. Enteroenteric or enterocolic fistulas involve either the small or large intestine connecting to another structure in the body. Enterovaginal fistulas are fistulas involving the vagina. Enterovesicular fistulas enter the bladder and can cause the person to contract frequent urinary tract infections.

Symptoms

Symptoms of fistulas vary depending on their location and severity. However, some symptoms are common in most cases. People often feel very unwell and run a fever. They also feel pain or tenderness at the site of the fistula. Itching may develop, especially if the fistula involves skin. Fistulas often exude pus, which may have an unpleasant or foul smell.

Fistulograms for Diagnosis

A fistulogram is a special type of x-ray used to get a more detailed image of a fistula. During the procedure, a dye is injected into the fistula to make it more visible on x-ray images. If the fistula connects to the outside of the body, a catheter inserts the dye. If the person has a fistula in their rectum, the doctor will inject the dye via the anus before taking x-rays from a variety of angles. This helps doctors to see the fistula from several different positions.

Intravenous Pyelogram

An intravenous pyelogram is an X-ray common in diagnosing bladder fistulas. The person may be asked to stick to a diet of clear liquids or fast altogether before the procedure. This is to make sure that the colon does not contain any stools at the time of the x-ray that may block the surgeon’s view of the bladder. The doctor injects the dye into a blood vessel, usually in the arm, then takes several x-rays from different angles to get a clear view.

Fistulas and Sepsis

If left untreated, fistulas can become chronic. They can also cause sepsis, a potentially life-threatening condition that develops when the immune reacts to an infection. Symptoms of sepsis include a high-grade fever, a rash, and confusion. It can also result in a fast heart and breathing rate. Sepsis is a medical emergency and requires immediate hospital treatment.

Risk Factors

Certain conditions place a person at a higher risk of developing a fistula. Crohn’s disease and diverticular disease are two conditions highly likely to cause fistulas. Around one in three people with Crohn’s disease will get a fistula at some point. Certain cancer therapies, in particular, radiation therapy, can make fistulas more likely to form. An unusual cause of enterovaginal fistulas is obstructed labor when doctors delay intervention for too long. This is rare in the United States as women usually receive a high level of care during childbirth.

Medications for Fistula Treatment

There is not currently a medication that can cure fistulas. However, medication may be used as part of a treatment program. Doctors often prescribe antibiotics to help clear up the infection causing or worsening the condition of the fistula. People with Crohn’s or diverticular disease may take medication, usually anti-inflammatories, that can help stop an existing fistula from worsening and prevent new ones from developing.

Treatment with Enteral Diet

Doctors may prescribe enteral diets to those with fistulas in the small or large intestines. When a person is on an enteral diet, they will consume only liquid food for a period. They may require a feeding tube. This type of diet ensures one receives all the nutrients they need without taking in any solid food, thus reducing the amount of stool passing through the intestines and rectum. With this treatment, the fistula has a chance to heal and may even close on its own.

Non-Invasive Treatments

If the fistula is small, doctors may use a minimally-invasive technique to manage it. One option is to attempt to seal the fistula using a special adhesive called fibrin glue. Alternatively, doctors may plug up the fistula. This is often done using collagen. In addition to these methods, infected fistulas will usually be drained of fluid using a catheter to help manage the infection.

Surgical Intervention

If the fistula is large or does not respond to less invasive treatments, it will require surgical removal or repair. Where possible, surgeons will use laparoscopic methods, inserting cameras and tools through very small incisions. However, some fistulas require transabdominal surgery involving larger incisions in the abdominal wall. In some cases, a fistula may develop in a diseased part of the bowel. Doctors may resection the bowel and remove the diseased section, including the fistula. In this situation, the person may require a pouch after surgery. This will temporarily divert stool away from the resectioned area to give it time to properly heal.