If you have Crohn's and have been struggling with the area around your back passage — abscesses that keep coming back, a fistula that will not quite settle, or unusual fissures — please know this is common. About one in three people with Crohn's develops problems around the anus at some point, and for some it actually appears before the bowel symptoms show up.
The most common things you might be dealing with are: an abscess (a painful pocket of pus around the anus), a fistula (an abnormal little tunnel that drains fluid from the inside of the bowel to the skin), an unusual fissure (a tear, sometimes painless and in an unexpected position), and large or inflamed perianal skin tags. Many people experience a combination of these over time.
Crohn's perianal disease behaves differently from the same problems in people without Crohn's, and it needs a different approach — usually a careful combination of medicines (to settle the Crohn's itself) and surgery (to manage what is happening locally). One without the other rarely works well. The good news is that with both working together, the outlook is much better than it used to be.
Crohn's is a condition where parts of the gut become chronically inflamed. The inflammation can go deep — through the full thickness of the bowel wall and sometimes into surrounding tissues. Near the anus, this is what leads to small tunnels (fistulas) forming, pockets of infection (abscesses), and damage to the skin around the area.
It is not entirely understood why some people with Crohn's develop perianal problems and others do not — but it is more common when the Crohn's involves the colon or rectum. This is not something you have caused or could have prevented.
What you notice depends on what is happening at the time — and many people experience different things at different points.
An abscess usually announces itself loudly: acute pain, a tender swelling, sometimes a fever, and a sense that something is clearly wrong. A fistula is often more constant: ongoing fluid or pus seeping through the skin, sometimes with mild background pain, sometimes with episodes when it flares up. Crohn's fissures can be confusing — they can sit in unusual positions, be painless, or come with large fleshy skin tags that other doctors may not recognise as part of the picture.
If you have Crohn's and you have noticed any of this — especially if you have been quietly putting up with it — please bring it up at your next appointment. Earlier treatment is gentler and almost always more effective. There is nothing to be embarrassed about.
For most patients with Crohn's fistulas, the first investigation is an examination under anaesthetic (EUA) — examining the area carefully under a short general anaesthetic, so you do not feel any of it. The EUA usually does two things at once: it maps out where the fistula tracts run and identifies any pockets of infection, and anything found can also be treated at the same sitting — draining an abscess, placing a seton if appropriate, and so on. For most patients, the diagnostic step and the first treatment step happen on the same day.
An MRI of the pelvis is often used to add detail to what the EUA shows, particularly for complex, deep, or recurrent fistulas. It is not painful, just half an hour or so lying still in the scanner. Sometimes the MRI is done before the EUA to help plan; sometimes afterwards to clarify; sometimes both. A colonoscopy may also be arranged to assess how the Crohn's is behaving elsewhere in your bowel.
The investigation phase can feel exposing, particularly because the symptoms are private. The team is very used to this kind of assessment and approaches it gently and respectfully — your dignity matters as much as the medicine.
Perianal Crohn's almost always needs both medical and surgical treatment, working hand in hand. The combination is what makes the difference — neither half alone is usually enough.
A typical plan involves several elements: biologic therapy (medicines like infliximab, adalimumab, vedolizumab, or ustekinumab) from your gastroenterologist to settle the underlying Crohn's, because that is the engine driving everything else; seton placement for complex fistulas, which is a small soft loop passed through the fistula and tied loosely — it keeps the tract drained, prevents abscesses from forming, and protects the sphincter while the medicines do their work; abscess drainage done promptly whenever an abscess forms, for rapid relief; antibiotics in selected cases; and definitive surgery — actually closing a fistula — only once the Crohn's is well controlled and the tract is mature, and only in carefully selected patients.
Throughout all of this, protecting the sphincter muscle (the ring of muscle that controls continence) is the central principle. Every decision is weighed against the risk of damaging continence, and gentler options are always considered first.
Mr Nguyen works as part of a partnership with your gastroenterologist — both of you, your gastroenterologist, and Mr Nguyen working together, not in separate silos. His role usually involves: performing the EUA and reviewing the MRI to map out the fistula anatomy; draining any abscesses promptly; placing setons to keep things settled while the medicines work; and, when the time is right, performing definitive surgery to close a fistula once the Crohn's is well controlled.
Many patients live with a seton for months — sometimes longer — and this is normal, not a setback. The seton is quietly doing its job in the background, preventing abscesses while everything else settles. See the Seton Care guide for what daily life with a seton actually looks like — most people are surprised at how unobtrusive it becomes.
Honest, unhurried communication is part of the approach. You will always understand what is happening, why, and what to expect next.
If you have Crohn's and notice new perianal pain, swelling, fever, fresh discharge, or a new lump, please contact your gastroenterologist or our rooms promptly. Acute abscesses need timely drainage — the longer they are left, the more uncomfortable and disruptive they become.
Chronic discharge, recurrent pain, or a sense that things are not quite right also warrants reassessment, even if your Crohn's elsewhere seems well controlled. Please do not put up with it quietly.
If you develop new perianal symptoms, you will be examined, an MRI is arranged if needed, and a plan is discussed with your gastroenterologist before anything is started. Most patients with active perianal Crohn's settle well on long-term combined biologic therapy and a seton, and the great majority return to a normal quality of life. The path is sometimes a bit winding — but it leads somewhere good.
Many patients achieve long-term, durable improvement — particularly with biologic therapy combined with careful surgical management. A complete "cure" in the sense that the underlying Crohn's disappears is harder, because Crohn's itself is a chronic condition. But long, symptom-free periods and a normal quality of life are realistic and common.
A small proportion of people with very severe, refractory perianal Crohn's eventually need a temporary or (occasionally) permanent stoma to give the area a chance to heal. The vast majority of people do not. The whole point of combined medical–surgical management is to avoid this where possible — and for most patients, that goal is met.
Sometimes — but only for simple, low fistulas, and only when the Crohn's is well controlled. Cutting a complex fistula in someone whose Crohn's is still active leads to poor healing and risks damaging the sphincter, which can affect continence. For most patients with Crohn's fistulas, a seton is the safer and kinder first step.
Often several months while the biologic therapy takes effect. Some patients keep a seton long-term as a permanent management strategy — particularly if the fistula is complex and they are otherwise well. It is comfortable once the initial healing has settled, and the day-to-day care is straightforward — see the Seton Care guide for the practical details.
It is almost never too late. Perianal Crohn's management has changed substantially over the last decade — biologic therapies that did not exist before are now part of the standard approach, and combined medical–surgical care reliably gets people who were previously stuck to a much better place. If you have been told there is nothing more to do, a fresh assessment is worth it.
Have questions about crohn's perianal disease?
Mr Nguyen sees patients at his consulting rooms in Heidelberg and operates at Warringal Private and Epworth Eastern. A GP or specialist referral is required.