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.
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.
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 sitDischarge of feces, blood, or pus through the fistula opening in the skin
Fistula between the small and large intestine
DiarrheaPassing food that hasn’t been digested
Fistula between the intestine and bladder
Passing gas, stool, or pus when you urinateUrinary tract infectionPainful urination with a burning sensationCloudy or bloody urineUrgent need to urinate
Fistula between the intestine and vagina
Passing gas or stool through the vaginaPainful sexual intercourse
Fistula from the bowel to skin
Boil on skinSkin abscess that may drain pus or stoolDehydration, malnutrition, diarrhea
Diagnosis
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:
What are my options for fistula removal?What preparations will I need to make if I have fistula removal surgery?What are the potential complications from surgery?What kind of restrictions will I have after my surgery?How long will it take me to recover from fistula removal surgery?Will I need additional surgeries?
Summary
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.
