Definition and Overview

A fistula is an abnormal connection that develops between two body parts that are separate from each other. Fistula is the Latin word that directly translates into “pipe” or “tube.” Generally, the presence of fistulas indicates a disease, but there are instances when a surgeon creates a fistula between two epithelialized surfaces for treatment purposes.

There are different kinds of fistulas and they can be present in different parts of the body. Here are some examples of fistulas and where they can be found:

  • Arteriovenous fistula, when the abnormal connection is present between a vein and an artery.
  • Biliary fistula, often surgically created to connect bile ducts to the surface of the patient’s skin.
  • Cervical fistula, often found in the patient’s cervix or the neck area.
  • Craniosinus fistula, which exists in the space between the patient’s nasal sinuses and inside the skull.
  • Enterovaginal fistula, located between the patient’s vagina and the bowels.
  • Anal or fecal fistula, often found connected to the intestines.
  • Gastric fistula, a connection between the surface of the patient’s skin and the stomach.
  • Metroperitoneal fistula, located between the patient’s peritoneal cavity and the uterus.
  • Umbilical fistula, an abnormal connection between the patient’s gut and navel.
  • Pulmonary arteriovenous fistula, often found in the patient’s lung, connecting a vein and the pulmonary artery. This type of fistula allows the oxygenation of the blood without passing through the lung.

Fistulas are categorized according to the structure of the connection.

  • Blind fistulas often have one open end but are connected to two structures.
  • Complete fistulas have openings on both ends.
  • Horseshoe fistulas are often found in the anal area where they connect the anus and the skin surface after circling (in a horseshoe pattern) the rectum.
  • Incomplete fistulas are tube-like structures stemming from the skin but are closed on both ends and do not connect to any structures inside the patient’s body.

Causes of Condition

Fistulas can be caused by a wide variety of factors. One of them is disease. Typically, when fistulas are located in the bowels, one can easily conclude that they are caused by an inflammatory disease in the bowels. Chrohn’s disease, for example, is considered as the leading cause of different types of fistulas, including enteroenteral, anorectal, and enterocutaneous fistulas. In some cases, a person suffering from a serious case of hidradenitis suppurative (or HS), a chronic disease often diagnosed by the presence of abscess and cyst clusters, will have fistulas in different parts of the body, including the underarms, the inner thighs, buttocks, groin, and under the breasts. HS is not a contagious disease and may be characterized by long periods of inflammation in the affected areas.

Surgical treatment can also cause the presence of fistulas. For example, gallbladder surgery, when performed incorrectly or carelessly can result to biliary fistula. In some cases, patients undergoing radiation therapy can also have vesicovaginal fistula. Fistulas can also be deliberately created as a form of treatment. For example, patients suffering from late-stage renal failure might be prescribed a cimino fistula—or an artificial connection between the skin surface of the arm and a vein—in order to facilitate the easier withdrawing of blood for hemodialysis treatment. Patients suffering from portal hypertension can also be prescribed a portacaval fistula, a connection between the inferior vena cava and the hepatic portal vein for treatment.

Trauma can also be a cause of fistulas. In patients who have suffered trauma to the head, perilymph fistulas can also surface. Perilymph fistulas are generally found in the inner ear, which can leak perilymph into the middle part of the ear (normally filled with air instead of liquid). Arteriovenous fistulas can also be caused by trauma to different parts of the body. Women who have undergone obstructed labour can also develop rectovaginal and vesicovaginal fistulas.

Obstetric fistulas can also result from obstructed labor, when the blood supply of the bladder and vaginal tissues are cut off during the procedure. When the tissues of the bladder and vagina die, due to the lack of blood supply, a fistula will form and can be the involuntary passage for fecal matter and urine.

Multiple rapes or rape by foreign objects can also result in rectovaginal and vesicovaginal fistulas.

Key Symptoms

Symptoms vary among different kinds of fistula, and in many cases, the fistula grows undetected for long periods of time, other than being an unsightly indent on the skin.

In the case of fistulas found between the bowels, digesting food can be difficult for the digestive system. In some patients, bowel-to-bowel fistulas can lead to prolonged periods of diarrhoea and malnourishment. In many cases, internal fistulas are not characterized by observable symptoms and can only be detected by X-ray or other medical imaging methods.

Anal fistulas, on the other hand, are perhaps the most observable kind. They are characterized by symptoms such as skin irritation in the anal area, painful passing of bowels, and pain when sitting down or engaging in various positions that affect the skin and muscles in the area. Some anal fistulas also leak fecal matter.

Rectovaginal and vesicovaginal fistulas are often characterized by pain, infection, or inflammation around the vaginal area. Fistulas connected to the bladder can also sometimes leak urine or fecal matter (typically during urination).

Who to See and Types of Treatments Available

If you are experiencing the symptoms described above or suspect that you have internal fistulas, it would be best to consult your regular physician who can recommend tests and scans to diagnose the presence of such abnormal connections.

Treatments for fistulas vary depending on the types and kinds, but typically, a doctor would recommend medication or a combination of antibiotic therapy and surgery. It is best to consult with a specialist in the area where the fistulas are found to develop the best treatment regimen.


  • National Association for Colitis and Crohn’s Disease
  • Identification of Monarda fistulosa. Discover Life
  • NHS Choices: Anal Fistula
  • American Society of Colon and Rectal Surgeons
  • National Cancer Institute
  • Sleisenger and Fordtran’s Gastrointestinal and Liver Disease
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