Gastrointestinal Fistula

Medically Reviewed By William C. Lloyd III, MD, FACS

What is a gastrointestinal fistula?

A fistula is an abnormal passageway that forms between two body structures that usually do not connect. A gastrointestinal (GI) fistula is an abnormal connection between either the stomach or intestines to another body part. This could include other parts of the intestine, the skin, or other organs, such as the bladder or vagina. This abnormal connection allows GI fluids and material to leak into areas where they should not be.

GI fistulas usually develop as a result of disease, injury or surgery. People with underlying digestive diseases are at increased risk of developing a GI fistula. Examples include Crohn’s disease and diverticular disease. GI cancers and radiation therapy to treat them also increase the risk of a fistula.

The symptoms of a GI fistula depend on the organ to which it connects. Some fistulas may not have any symptoms. Fistulas that connect to the skin may be obvious, with an opening and noticeable leakage. When the connection is internal, signs and symptoms can be general. Abdominal pain or diarrhea may be the only symptoms. Fistulas that connect to other organ systems can result in frequent infections of the organ or fecal material showing up in places where it should not be, such as the vagina.

Treatment depends on where the fistula is and what symptoms it is causing. Sometimes, nonsurgical treatment with antibiotics and other medicines allows the fistula to heal on its own. In other cases, surgery to repair the fistula is necessary.

Left untreated, a GI fistula can result in serious and life-threatening complications like malnutrition, dehydration and infection. Seek immediate medical care if you notice an opening in the skin of your belly or in your genital or perianal area. You should also seek prompt medical care if you have major changes in your bowel habits, such as severe diarrhea, gas or pain.  

What are the symptoms of a gastrointestinal fistula?

Signs and symptoms of a GI fistula will vary depending on where the connection is. Sometimes, there are no obvious symptoms of a GI fistula. For example, a fistula that connects two nearby areas of the small intestine may not produce any symptoms. Doctors tend to find these fistulas on an imaging exam for another reason.

GI fistulas that connect to the skin are usually very noticeable. There will be an abnormal opening in the skin draining or leaking fluids, blood, or fecal material.

GI fistulas that join two distant parts of the digestive tract or another organ can cause symptoms including:

  • Abdominal pain or pain in the area between the genitals and anus (perineum)

  • Diarrhea or gas, which may be severe

  • Painful or uncomfortable sex in women

  • Passage of fecal material or intestinal gas in the bladder, vagina, or stomach (belching that smells like fecal matter)

  • Recurrent UTIs (urinary tract infections)

  • Weight loss

GI fistulas can lead to serious and life-threatening malnutrition, dehydration, electrolyte imbalances, and infection. Prompt treatment is necessary to prevent these complications.

If you have a digestive disease that puts you at risk for a fistula, it’s important to see your doctor regularly. You should also promptly report any changes in your bowel habits or symptoms. Similarly, people who have recently had abdominal surgery should watch closely for signs of a problem and report any changes to their doctor immediately.

What causes gastrointestinal fistula?

Up to 85% of GI fistulas develop as a complication following abdominal surgery. The rest occur as a result of inflammation or infection in the abdomen. Underlying causes of this include:

  • Appendicitis

  • Cancer in the abdomen and radiation therapy to treat it

  • Diverticular disease

  • Inflammatory bowel disease including Crohn’s disease and ulcerative colitis

  • Intestinal blockage

  • Perforated peptic ulcer

  • Trauma to the abdomen including motor vehicle accidents, stabbings, and gunshot wounds

What are the risk factors for gastrointestinal fistula?

There are no general differences in age, sex or race for developing a GI fistula. However, having an underlying digestive disease can increase the risk.

Crohn’s disease is the most common underlying cause of GI fistulas. Up to 40% of people with the disease will have a fistula at some point. In this group, fistulas most commonly occur between the intestines and skin and the bowel and anus. Up to 12% of people with diverticulitis and 10% of people receiving abdominal radiation will also develop GI fistulas.

Treating the disease and keeping it under control will help avoid fistula development. Seeing your doctor regularly is vital to controlling chronic diseases, such as Crohn’s disease and diverticular disease.

How do doctors treat a gastrointestinal fistula?

Ideally, doctors treat GI fistulas with medications and supportive measures to help the fistula heal and close. This can take up to three months. The goals of treatment during the healing process include:

  • Controlling fluid drainage and protecting the skin

  • Preventing and treating infection with antibiotics

  • Providing adequate nutrition and hydration, which may require nutrition through a vein or feeding tube

  • Treating the underlying cause, which may involve immunosuppressant drugs to regain control in the case of Crohn’s disease

When the fistula does not close with adequate treatment, surgery may be necessary to repair it.

What are the potential complications of gastrointestinal fistula?

When your overall health is good, there is an excellent chance of recovering smoothly from a GI fistula. However, GI fistulas can lead to serious complications, including malnutrition, dehydration, infection and sepsis. These complications can be life threatening if left untreated.

Was this helpful?
  1. Abscess and Fistula Expanded Information. American Society of Colon and Rectal Surgeons.
  2. Enterocutaneous Fistula. Regents of the University of California.
  3. Fistula. U.S. National Library of Medicine.
  4. Gastrointestinal Fistula. U.S. National Library of Medicine.
  5. Intestinal Fistulas. Medscape.

Medical Reviewer: William C. Lloyd III, MD, FACS
Last Review Date: 2021 Apr 15
View All Digestive Health Articles
THIS TOOL DOES NOT PROVIDE MEDICAL ADVICE. It is intended for informational purposes only. It is not a substitute for professional medical advice, diagnosis or treatment. Never ignore professional medical advice in seeking treatment because of something you have read on the site. If you think you may have a medical emergency, immediately call your doctor or dial 911.