Fistulas and Crohn’s Disease: What to Know

Medically Reviewed by Minesh Khatri, MD on June 02, 2024
5 min read

Fistulas are small tunnels that form between two organs or an organ and the surface of your body. They’re due to inflammation from your Crohn’s disease, which causes sores to form on your intestinal wall. In Crohn’s disease, they often form in your butt. They can also form in your intestines, bladder, or straight through the bowel wall to your skin surface. You may even develop a fistula between your butt and vagina.

They sound scary but are very common with Crohn’s disease. In fact, it’s estimated that up to half of all adults with this condition will eventually have a fistula.

There are several types of fistulas you may get if you have Crohn’s disease. They include:

  • Anal fistula. This is the most common type of fistula among patients with Crohn’s disease. Symptoms include a painful bump or boil around your butt. You may see an open skin abscess that drains fluid or poop.
  • Bowel-to-bladder fistula. You may have frequent urinary tract infections. It may hurt to pee, and your urine may look cloudy or have blood in it.
  • Bowel-to-vagina fistula. You may notice that you pass gas or poop through your vagina.
  • Bowel-to-skin fistula. These often occur on your stomach. The contents of your gut leak out, which hurts your skin and causes it to become very red and sore. You are also more at risk of a skin infection.
  • Bowel-to-bowel fistula. This is when different parts of your gut link together, like your small and large intestines. It can cause diarrhea and even malnutrition and dehydration due to loss of nutrients.

Fistulas are usually diagnosed through a physical exam, as well as imaging tests such as CT scans, ultrasounds, and MRIs.

If you have a simple anal fistula, your doctor may recommend that you treat it with antibiotics, plus any treatment you already take for your Crohn’s disease, such as an anti-tumor necrosis factor agent like infliximab. But if you have a more complex anal fistula, or another type of fistula, like a bladder or vaginal one, you may need surgery, especially as these types of fistulas tend to pass through muscle layers or organs. Options include:

A seton. This is a thin surgical cord that’s put into the fistula to help drain infection and allow it to heal. It’s left in for several weeks and removed once the fistula starts to heal. Studies show that this treatment is most effective when it’s done at the same time as anti-TNF therapy. It can feel funny – like rubber bands hanging out of your butt – but after a few days, you won’t notice that the cord is there.

A medical plug. This is a cone-shaped plug made from animal tissue that blocks the internal opening of the fistula.

Fistulotomy. The fistula is cut open (the way you would a cardboard tube) and flattened out. It can take anywhere from a week to several months to heal.

Ligation of the intersphincteric tract (LIFT). This is for more complex anal fistulas. A cut is made in the skin above the fistula, and the sphincter muscles are moved apart. The fistula is then sealed at both ends so poop doesn’t get into it.

Medical glue. This is a nonsurgical option, where your doctor injects a glue into your fistula while you’re under general anesthetic. This helps seal the fistula, so that it heals. It’s thought to be less effective than a fistulotomy, but it’s less invasive.

You may need an ileostomy while your body heals from fistula surgery. This is a procedure where your small intestine is brought up through the abdominal wall so that your poop can leave your body through a surgically created hole known as a stoma. Your poop will be collected in an ostomy bag. This is temporary, but you may need more surgery to make sure your intestine has fully closed where the fistula was.

Researchers are also studying an experimental treatment for fistulas using stem cells. These are injected directly into the fistula. The thought is they are able to repair damaged cells and ramp down some of the inflammation associated with Crohn’s disease. A 2021 review published in the journal Stem Cell Research & Therapy looked at 29 studies and concluded that patients given stem cell injections had higher rates of healing than those given a placebo. But more research is necessary to determine how helpful it really is.

Most fistulas respond well to surgery. Your doctor may recommend that you soak the area in a warm bath, or sitz bath, and that you take stool softeners or laxatives for a week. This helps keep your poop soft, so it doesn’t irritate the area.

Your doctor may also prescribe pain pills for you to take for a few days after surgery. Local anesthetics like lidocaine can also temporarily relieve discomfort.

You’ll be followed closely to make sure that the fistula doesn’t return and that new ones don’t develop.

The best way to help prevent a fistula is to be on a therapy that helps keep your Crohn’s disease under control. A 2020 study published in JAMA Network Open, for example, found that children and young adults with Crohn’s disease who used nonsteroid therapies such as azathioprine or methotrexate (both immune system suppressors) or the anti-TNF drug infliximab were nearly 60% less likely to have fistulas than those who didn’t. If they did go on to develop one, they were 55% less likely to need ostomy surgery. This is especially important because kids with Crohn’s disease are almost twice as likely to get fistulas as adults, possibly because the condition in this age group tends to be more aggressive.

If you have a fistula and your doctor recommends surgery, it’s important to talk to them about the following:

  • Surgery options
  • Pre-surgery prep
  • Potential complications
  • Restrictions after surgery
  • Recovery time
  • How the surgery will affect your diet and bowel movements
  • Whether you will need an ileostomy, and if you do, how to care for your ostomy pouch
  • Home supplies
  • Follow-up care

While fistulas are a common complication of Crohn’s disease, the good news is there are effective treatments out there to both remove them and prevent them from returning.