Preventing a fistula depends on what type you’re trying to avoid, but the core strategies come down to managing the conditions that cause them: abscesses, inflammatory bowel disease, and in the case of obstetric fistulas, prolonged obstructed labor. Most anal fistulas develop from untreated or recurring abscesses near the anus, while obstetric fistulas result from complications during childbirth. Both are largely preventable with the right timing and care.
How Anal Fistulas Form
An anal fistula is an abnormal tunnel between the inside of the anal canal and the skin near the anus. It almost always starts with a perianal abscess, a pocket of infection in the tissue around the anus. Between 30% and 50% of people who have an abscess drained will eventually develop a fistula in the months or years that follow. In many cases, 30% to 70% of patients already have a fistula forming by the time they show up for abscess treatment.
That makes the abscess stage the critical window for prevention. Catching an abscess early, before it has time to create a chronic tract through surrounding tissue, is the single most effective way to prevent a fistula from developing.
Recognize an Abscess Early
A perianal abscess typically announces itself with throbbing pain near the anus that gets worse when you sit down or have a bowel movement. You may notice a firm, swollen lump near the anus that feels warm to the touch, sometimes with redness. Fever and chills can follow if the infection spreads. Some abscesses drain on their own, and the temporary relief can make people assume the problem is gone. It isn’t. An abscess that keeps coming back is a strong signal that a fistula tract has already formed or is forming, and it needs medical attention, not just warm soaks at home.
The key is getting proper drainage before the infection has time to burrow deeper into surrounding tissue. If you notice persistent pain, swelling, or discharge near the anus that lasts more than a day or two, that’s worth a visit to your doctor rather than waiting it out.
Reduce Your Risk With Diet and Lifestyle
Constipation and straining during bowel movements create pressure that can damage the small glands inside the anal canal, setting the stage for infection. Keeping your stools soft and regular is one of the simplest ways to protect those glands.
The National Academy of Medicine recommends the following daily fiber intake for adults:
- Women 50 or younger: 25 grams
- Women over 50: 21 grams
- Men 50 or younger: 38 grams
- Men over 50: 30 grams
Fiber works best when it absorbs water, which makes stool soft, bulky, and easier to pass. Drinking plenty of water throughout the day is just as important as the fiber itself. Most people fall well short of these targets, so adding fiber gradually through whole grains, fruits, vegetables, and legumes can make a noticeable difference in bowel regularity within a few weeks.
Smoking Is a Major Risk Factor
Smoking dramatically increases the likelihood of developing anal abscesses and fistulas. A study published in the Chinese Medical Journal found that current smokers had roughly 12 times the odds of developing abscess or fistula disease compared to nonsmokers. Former smokers, interestingly, showed no significant increase in risk, which suggests that quitting can bring your risk back toward baseline. If you smoke and have had any issues with perianal abscesses, this is one of the most impactful changes you can make.
Managing Crohn’s Disease to Prevent Fistulas
Crohn’s disease is one of the leading causes of complex anal fistulas. The chronic inflammation it creates in the intestinal wall can erode through tissue and form tunnels between organs or between the intestine and skin. For people with Crohn’s, preventing fistulas means controlling the underlying inflammation aggressively and early.
Biologic medications that block a specific inflammatory protein called TNF are the first-line treatment for fistulizing Crohn’s disease and the only class with strong evidence from randomized trials specifically designed to measure fistula healing. Starting these medications early is preferred over waiting, because delaying treatment allows fistula tracts to mature and become harder to close. Steroids, despite being common in Crohn’s treatment overall, are ineffective for fistula prevention and can actually worsen the situation by increasing infection risk and discharge.
If you have Crohn’s and develop perianal pain, swelling, or drainage, bringing it up with your gastroenterologist promptly matters. Early combination treatment, often a small flexible drain placed in the fistula tract alongside biologic therapy, is both safe and reasonably effective at preventing the fistula from becoming a chronic problem. For patients who don’t respond to first-line biologics, newer oral medications and alternative biologic classes have shown promise as second-line options.
Diabetes and Fistula Risk
Diabetes is an independent predictor of both fistula development and recurrence after surgery. People with diabetes who undergo fistula repair face nearly five times the odds of recurrence compared to those without diabetes. High blood sugar impairs wound healing and immune function, which makes it harder for the body to clear infections and repair tissue damage. If you have diabetes, keeping your blood sugar well controlled is a practical step toward reducing your fistula risk, especially if you’ve already had an abscess or previous fistula.
Preventing Fistula Recurrence After Surgery
If you’ve already had a fistula treated surgically, preventing it from coming back is a real concern. Overall recurrence rates sit around 12.5%, but that number varies enormously depending on the complexity of the fistula and the type of surgery performed.
Simple fistulas recur about 6% of the time, while complex fistulas come back in roughly 25% of cases. The surgical approach matters too. Procedures that cut through part of the sphincter muscle to eliminate the fistula tract have recurrence rates under 5%, while sphincter-sparing techniques, which preserve muscle to protect continence, carry recurrence rates above 48%. Plug and graft procedures have recurrence rates exceeding 50%. This tradeoff between recurrence risk and continence preservation is something to discuss thoroughly with your surgeon before choosing a procedure.
The strongest predictors of recurrence are diabetes, a history of anorectal abscess before the fistula, having a complex fistula, and the type of surgical repair. Addressing the modifiable factors on that list, particularly blood sugar control and treating abscesses promptly rather than letting them recur, gives you the best chance of a lasting repair.
Preventing Obstetric Fistulas
Obstetric fistulas are a different condition entirely. They form when prolonged, obstructed labor compresses the tissue between the baby’s head and the mother’s pelvic bones for so long that the tissue dies, leaving a hole between the bladder or rectum and the vagina. This type of fistula is rare in high-income countries but remains a significant problem in regions with limited access to emergency obstetric care.
The most effective prevention strategies target the causes of prolonged labor. Access to emergency cesarean delivery when labor stalls is the single most important intervention. Skilled attendance during delivery allows early identification of danger signs. When obstructed labor does occur, inserting a catheter to relieve pressure on the bladder for one to two weeks can prevent tissue death from progressing. For small, fresh fistulas caught immediately, catheter drainage alone allows 40% to 95% of them to heal on their own over four to six weeks without surgery.
Birth preparedness, quality prenatal care, and education about recognizing warning signs during labor all contribute to prevention. In areas where these resources are limited, strengthening health facilities to provide emergency obstetric and newborn care is the public health priority that would prevent the vast majority of cases.