What is a fistula? Types, symptoms, treatments

Yael Cooperman, MD - Contributor Avatar

Reviewed by Yael Cooperman, MD, Ro, 

Written by Gina Allegretti, MD 

Yael Cooperman, MD - Contributor Avatar

Reviewed by Yael Cooperman, MD, Ro, 

Written by Gina Allegretti, MD 

last updated: Mar 29, 2022

4 min read

Each organ in your body has its own distinct role. For example, your intestines carry food and waste, your bladder holds urine, and your lungs bring in fresh oxygen. An organ usually keeps its contents to itself, so you don’t wind up with stool in your bladder or food in your lungs. But if you have a fistula, this is exactly the type of scenario that may occur.  


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What is a fistula? 

A fistula is an abnormal connection or passageway between two of your body’s structures, like your organs or blood vessels. 

Sometimes, healthcare providers make fistulas on purpose to help manage certain medical conditions (more on that later). However, most fistulas occur due to infection, inflammation, or injury. For example, if an injury occurs in the digestive system during surgery, as the tissue heals, it may develop a connection to a nearby structure like the bladder.

Types of fistulas

Fistulas vary based on their location and whether they’re part of another illness or made intentionally by a healthcare provider.

Anal fistula

One common type of fistula is an anal fistula (also called an anorectal fistula, perianal fistula, or fistula-in-ano) (Jimenez, 2021). 

It is a connection between the end of your digestive tract (the anal canal and anus) and the skin around it. It typically appears as a small hole or red, painful swelling next to the anus. Anal fistulas may cause complications like stool leakage (incontinence) or pain during bowel movements.

Anal fistulas can be caused by: 

  • Bacterial infection (anal abscess)

  • Blocked sweat glands in the anal canal (anal glands)

  • Inflammation: Conditions that cause inflammation throughout the digestive tract, such as inflammatory bowel disease (Crohn’s disease and ulcerative colitis) or diverticulitis

  • Sexually transmitted infections of the anus

  • Cancer or damage from radiation therapy for cancer treatment

  • Injury during surgery (trauma): During surgical procedures, an organ may be injured. As the tissue heals and grows, it can develop a connection to a nearby structure like the anus.   

Vaginal fistulas

The vagina can develop a fistula with nearby structures in the genital tract, digestive tract, and urinary tract. There are different types of vaginal fistulas, each named according to the structure involved. Types of vaginal fistula include: 

  • Vesicovaginal fistulas connect the vagina to the bladder 

  • Ureterovaginal fistulas connect the vagina to the tubes that run from the kidneys to the bladder (ureters) 

  • Rectovaginal fistulas connect the vagina to the rectum

Vaginal fistulas can be caused by damage to the vagina during childbirth or during a cesarean section (obstetric fistula) or other surgery. Some people are born with them, while others develop a fistula due to a sexually transmitted infection called pelvic inflammatory disease

Much like anal fistulas, vaginal fistulas can develop as a result of cancer in the colon (large intestine), uterus, or bladder, or from the radiation used to treat those cancers. 

Symptoms of a vaginal fistula depend on which structure it’s connected to. If the vagina is connected to the bladder, a person might experience urine leakage. If it’s connected to the rectum, they may have recurrent urinary tract infections (UTIs) or uterus infections or notice foul-smelling vaginal discharge due to stool in the vagina.

Tracheoesophageal fistulas

A tracheoesophageal fistula (TEF) connects the windpipe (trachea) and the esophagus, which is the tube that carries food from the mouth to the stomach. A TEF allows food and drinks to leak from the esophagus into the windpipe and lungs, causing choking, coughing, wheezing, or turning blue when you eat and drink. 

This type of fistula is often congenital, meaning that a person is born with it. It may also be caused by injuries during surgery or injury during the placement of a breathing tube (intubation). Like other types of fistulas, TEFs may be caused by cancer in a nearby organ (in this case, the trachea or esophagus. TEFs often require surgery to be repaired.

Arteriovenous fistulas (AV fistulas)

This type of fistula causes blood to flow from one blood vessel into another in a way it normally shouldn’t. 

Normally, blood rich in oxygen goes from the heart to the organs in a blood vessel called an artery and then goes back to the heart in a blood vessel called a vein. With an arteriovenous fistula, there’s a direct connection between an artery and a vein. 

AV fistulas are usually congenital (meaning you’re born with them) and can appear in the legs, arms, kidneys, brain, and lungs. 

Congenital AV fistulas are also called arteriovenous malformations (AVMs). Most people don’t know they have them unless they cause problems like: 

  • Severe swelling and bruising of the legs, blood clots in the legs

  • Headaches, seizures, bleeding in the brain

  • Difficulty breathing, coughing up blood, turning blue

  • Abdominal pain, blood in the stool, or vomit

A dialysis fistula is a special type of AV fistula that’s created intentionally by a healthcare professional in a person with certain kidney conditions. It’s used to perform dialysis, a process that helps remove toxins and provide fluids when the kidneys cannot do it themselves. 

How to treat a fistula

Some small fistulas don’t cause severe symptoms and may close on their own. Other fistulas may cause problems like pain or dangerous infections and may need treatment.

In the case of AV fistulas, if they’re small, a healthcare provider might recommend treating them with special stockings or gloves that compress the blood vessels and allow them to heal while taking medication to prevent blood clots (Lee, 2013). 

Depending on the location and type of fistula, treatment may involve a surgical procedure (fistulotomy). In some cases, a healthcare professional can use a tube called a catheter to allow the fistula to drain and close on its own (Bazi, 2007). They may also inject a substance into certain AV fistulas to plug the fistula (embolization) or use radiation to close a small fistula (stereotactic radiosurgery) (Zaki Ghali, 2019; Friedlander, 2007)

Left untreated, certain fistulas can cause severe and even life-threatening infections. If you have symptoms of a fistula, it’s important to be evaluated by a healthcare professional to understand if treatment is necessary. 


If you have any medical questions or concerns, please talk to your healthcare provider. The articles on Health Guide are underpinned by peer-reviewed research and information drawn from medical societies and governmental agencies. However, they are not a substitute for professional medical advice, diagnosis, or treatment.

  • Bazi, T. (2007). Spontaneous closure of vesicovaginal fistulas after bladder drainage alone: review of the evidence. International Urogynecology Journal and Pelvic Floor Dysfunction , 18 (3), 329–333. doi:10.1007/s00192-006-0194-7. Retrieved from https://pubmed.ncbi.nlm.nih.gov/17036168/

  • Friedlander, R. M. (2007). Clinical practice. Arteriovenous malformations of the brain. The New England Journal of Medicine NEJM , 356 (26), 2704–2712. doi:10.1056/NEJMcp067192. Retrieved from ​​ https://pubmed.ncbi.nlm.nih.gov/17596605/

  • Jimenez, M. & Mandava, N. (2021). Anorectal Fistula. StatPearls . Retrieved Mar. 31, 2022 from https://www.ncbi.nlm.nih.gov/books/NBK560657/

  • Lee, B. B., Baumgartner, I., Berlien, H. P., et al. (2013). Consensus Document of the International Union of Angiology (IUA)-2013. Current concept on the management of arterio-venous management. International Angiology: A Journal of the International Union of Angiology , 32 (1), 9–36. Retrieved from https://pubmed.ncbi.nlm.nih.gov/23435389/

  • Zaki Ghali, M. G., Kan, P., & Britz, G. W. (2019). Curative Embolization of Arteriovenous Malformations. World Neurosurgery , 129 , 467–486. doi:10.1016/j.wneu.2019.01.166. Retrieved from https://pubmed.ncbi.nlm.nih.gov/30735875/

How we reviewed this article

Every article on Health Guide goes through rigorous fact-checking by our team of medical reviewers. Our reviewers are trained medical professionals who ensure each article contains the most up-to-date information, and that medical details have been correctly interpreted by the writer.

Current version

March 29, 2022

Written by

Gina Allegretti, MD

Fact checked by

Yael Cooperman, MD

About the medical reviewer

Yael Cooperman is a physician and works as a Senior Manager, Medical Content & Education at Ro.