An Overview of Managing Crohn's Disease Fistulas

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Fistulas are abnormal tunnel-shaped openings that form in the intestine and connect to another organ. Fistulas affect up to half of people with Crohn's disease, a form of inflammatory bowel disease (IBD).

The most common site for a fistula is from the anal area to the skin, which is called a perianal fistula, but they can form between other organs as well. Fistulas need prompt medical treatment to control infection and other complications.

Read more about the symptoms of this serious but treatable condition, as well as how healthcare providers manage fistulas related to Crohn's disease.

Management and Treatment of Fistulas in Crohn's - Illustration by Jessica Olah

Verywell / Jessica Olah

Causes of Fistulas in Crohn's Disease

Crohn's disease is an inflammatory autoimmune disorder that affects the digestive system, mainly in the colon and end of the small intestine.

Fistulas develop when inflamed areas in the wall of the intestine lead to ulcers, abscesses, or other kinds of lesions that leak acidic gastric fluids. When untreated, the lesions grow larger until they connect to other organs.

Prevalence of Crohn's Fistulas

Fistulas are a common complication of Crohn's disease, affecting anywhere from 35% to 50% of people with the condition.

Signs and Symptoms

The signs of a fistula resulting from Crohn's disease vary depending on where the tunnel has formed and what organs it has reached.

Common areas for fistulas and their related symptoms are:

Anal or perianal fistula (from the rectum or anal canal to the skin)

  • Swelling or lump near anus, which may be painful when you sit
  • Discharge of feces, blood, or pus through the fistula opening in the skin

Fistula between the small and large intestine

  • Diarrhea
  • Passing food that hasn't been digested

Fistula between the intestine and bladder

  • Passing gas, stool, or pus when you urinate
  • Urinary tract infection
  • Painful urination with a burning sensation
  • Cloudy or bloody urine
  • Urgent need to urinate

Fistula between the intestine and vagina

  • Passing gas or stool through the vagina
  • Painful sexual intercourse

Fistula from the bowel to skin

  • Boil on skin
  • Skin abscess that may drain pus or stool
  • Dehydration, malnutrition, diarrhea


If your healthcare provider suspects a fistula, they will order tests to confirm the diagnosis, depending on the location.

Typical diagnostic tests for fistulas include:

  • Anal fistula diagnosis: Can include a physical examination, possibly performed under anesthesia to relax your sphincter muscles and avoid discomfort. Imaging tests such as an MRI or endoscopic ultrasound, in which a narrow tube is inserted into the rectum so providers can examine the area, are also used. Occasionally, healthcare providers order a fistulogram, in which dye is injected into the fistula to show detail on an X-ray.
  • Bowel to bladder fistula diagnosis: Cystoscopy is a procedure in which a healthcare provider examines your bladder while you are sedated, using a thin tube with a camera at the end. There is also a test called the poppy seed test. You will be asked to eat some poppy seeds and yogurt. The seeds won't be digested, and if you pass them when you urinate, it's an indication of a bladder fistula.
  • Bowel to vagina fistula: Imaging tests such as MRI, ultrasound, or possibly fistulography can be used. Sometimes blue dye is placed in the rectum and a tampon is placed in the vagina. If the tampon absorbs the blue dye, it indicates a vaginal fistula.
  • Bowel to skin fistula: Computed tomography (CT) scan of the abdomen or, if the fistula is in the colon, a barium enema can be used. You may also be asked to drink some barium for an X-ray procedure called esophagogram. Another option is a fistulogram.

Management and Treatment of Fistulas

If you develop a fistula, it generally won't heal without treatment, and they often recur. Healthcare providers will usually give you medication to reduce the inflammation, but surgery is often needed to close the fistula itself.

The primary management and treatment options for Crohn's disease fistulas include:

  • Antibiotics: Antibiotics can help correct the bacterial imbalance in your system due to the autoimmune response. Ciprofloxacin and metronidazole are two typical antibiotics prescribed for fistulas, as well as other symptoms of Crohn's disease.
  • Biologics: Biologics have revolutionized the treatment of Crohn's disease. They are antibodies, usually a type called TNF-alpha inhibitors, that are targeted to help stop certain types of inflammation. This can help fistulas heal and make their recurrence less likely. Adalimumab, certolizumab, golimumab, and infliximab are among the most widely used biologics. Newer biologics, like vedolizumab and ustekinumab, are also being used to treat perianal fistulas in Crohn's disease. Skyrizi (risankizumab-rzaa) is another biologic drug newly approved to treat those with moderate to severe Crohn's disease.
  • Immunomodulators: Medications like methotrexate and azathioprine are immunomodulators that suppress the whole immune system, as compared with the targeted therapy of biologics. They promote healing of fistulas and are sometimes used for long-term treatment of Crohn's disease.

Surgery is often needed to treat fistulas. Once the inflammation is under control, surgeons can remove or close the fistula.

The primary surgical options for fistulas include:

  • Fistulotomy: Outpatient procedure that cuts through the tunnel so the organs can function normally
  • Ileostomy: Reroutes the small intestine through the abdominal wall so that waste is removed through that opening
  • Fistulectomy: A procedure that removes the tunnel. There is a risk of damaging the sphincters (the muscles that control bowel movements), so it is performed only when necessary.

Surgeons may also place a plug or medical glue in the fistula to close it off.

Researchers are exploring regenerative medicine, which uses the body's own ability to heal, to treat perianal fistulas. Some early results are promising, showing that regenerative treatments like stem cell therapy repaired damaged perianal tissue. The process is still in clinical trials, however, and is not widely available. In the future, it may become a tool for treating fistulizing Crohn's disease.

Questions to Ask Your Doctor

If you have fistulizing Crohn's disease, your healthcare provider will want to begin treatment quickly. Here are some key questions for you to consider discussing with your gastroenterologist:

  1. What are my options for fistula removal?
  2. What preparations will I need to make if I have fistula removal surgery?
  3. What are the potential complications from surgery?
  4. What kind of restrictions will I have after my surgery?
  5. How long will it take me to recover from fistula removal surgery?
  6. Will I need additional surgeries?


Fistulas are abnormal openings that form between the intestine and other parts of the body. They are very common in people with Crohn's disease. Fistulas are treatable with antibiotics, biologics, and often surgery.

A Word From Verywell

Unfortunately, fistulas are a common complication of Crohn's disease. They are unpleasant and can be difficult to manage, but if you notice any of the symptoms, it's important that you get in touch with your care team right away. If infection spreads, it can lead to serious and even life-threatening complications such as sepsis. Today, an increasing number of people with Crohn's get their condition under control or into remission through the use of biologics, which will lower your chances of developing a fistula.

Frequently Asked Questions

  • Can your diet affect Crohn's disease?

    Though what you eat does not cause Crohn's disease, it can trigger flares. Generally, nutritionists advise limiting foods that are high in fiber or fat, as well as sodas and dairy products. You should work closely with your IBD care team to see if you can identify food triggers.

  • How do I know when I should go to the doctor for a Crohn's disease fistula?

    Fistulas can have serious complications, so if you notice any signs or symptoms, it's important that you contact your healthcare provider immediately. Even if you're not sure, it's better to discuss your symptoms with your gastroenterologist rather than ignoring them or thinking they will go away.

  • What will happen if my fistula is not treated?

    Fistulas can lead to many complications, including serious infections and sepsis, in which bacteria is spread through the bloodstream and can be life-threatening. There is also an increased risk of cancer due to untreated fistulas from Crohn's disease.

10 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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  3. University of California San Francisco. Enterocutaneous fistula.

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  6. Samaan M, Campbell S, Cunningham G, Tamilarasan AG, Irving PM, McCartney S. Biologic therapies for Crohn’s disease: optimising the old and maximising the new. F1000Res. 2019;8:1210. doi:10.12688/f1000research.18902.1

  7. Young C, Campbell K. Biologics versus Immunomodulators or Antibiotics for the Management of Fistulizing Crohn’s Disease: A Review of Comparative Clinical Effectiveness and Cost-Effectiveness. Canadian Agency for Drugs and Technologies in Health.

  8. Food and Drug Administration. SKYRIZI (risankizumab-rzaa) injection.

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By Nancy LeBrun
In addition to her extensive health and wellness writing, Nancy has written about many general interest topics for publications as diverse as Newsweek, Teen Vogue,, and Craftsmanship Quarterly. She has authored a book about documentary filmmaking, a screenplay about a lost civil rights hero, and ghostwritten several memoirs.