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Last reviewed: February 2021
Developing a fistula can be distressing, even if you’ve lived with Crohn’s Disease or Ulcerative Colitis for some time. You may find it difficult to talk about, even to people you normally confide in.
But you’re not alone. We’re here to support you and this information will:
This information is for people living with Crohn's or Colitis who have a fistula.
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A fistula is when a narrow tunnel develops that connects an organ to another part of your body. These tunnels can connect one internal organ to another, or to the outside surface of the body. A fistula can develop in any part of the body, but many involve the gut.
Around 1 in 3 (33%) people with Crohn’s develop a fistula at some time, and around 1 in 35 (3%) people with Ulcerative Colitis. Some people develop a fistula before Crohn’s or Colitis is diagnosed.
There are quite a few different types of fistulas.
Fistulas associated with Crohn’s:
Fistulas associated with Ulcerative Colitis:
Health professionals may also use some of these words to describe where a fistula is.
Word |
Meaning |
Type of fistula |
Peri |
around |
Perianal – around the anus |
Entero |
bowel or gut |
Enteroenteric – linking sections of the gut |
Cutaneous |
skin |
Enterocutaneous – opens onto the skin |
Vesical |
bladder |
Enterovesical – links to the bladder |
Colo |
colon – part of the bowel |
Enterocolonic – links colon to another part of the gut |
Although being diagnosed with a fistula is quite difficult and scary at the beginning, once you get used to the condition, it does get easier to deal with. Eventually you just get on with your life as normal and do most of the things you did before.
Claire
Living with Colitis
To understand the different types of anal fistulas and treatment options, it’s helpful to know about the structure of the muscles around the anus. Two doughnut shaped muscles, known as the anal sphincters surround the anal canal where poo travels. These allow you to control when you open your bowels to poo.
There are two sets of muscles:
Damage to these muscles can mean you have less control over wind, liquid, and sometimes even solid poo.
This shows the position of the muscles around the anal canal where poo travels. The pelvic floor muscles also help you to release pee, poo and wind and to delay this until you reach a toilet.
The name tells you where they are and if they involve the external or internal sphincters.
It’s not yet fully understood what causes fistulas, but certain genes and gut bacteria may play a role in their development. If you have Crohn’s, the cells involved in healing may not work as they should.
Fistulas are more common if you have Crohn’s. This is because gut inflammation can spread through all the layers in the bowel wall.
This can cause small leaks and abscesses to form. As the abscess develops it may hollow out a chamber or hole. This can become a channel linking the bowel to:
If the abscess bursts, the pus may drain away, but the channel may remain as a fistula. Fistulas can occur anywhere in the bowel. The longer you have Crohn’s, the more likely you are to develop a fistula.
In Ulcerative Colitis the inflammation doesn’t spread through the full thickness of the bowel wall, so fistulas are less likely to form.
First, your doctor will carry out a physical examination of the skin around the anus, as fistulas can be seen as tiny holes or raised red spots. The doctor may press on the skin around the fistula to see if there is leakage of pus or poo. For some fistulas, you may have a general anaesthetic so that the area can be examined while you sleep. This is because the examination is painful and it’s helpful to have the anal sphincters and pelvic floor muscles fully relaxed. This is known as examination under anaesthetic or EUA. Sometimes a special probe is used to trace out the route of the fistula. As well as finding out whether the fistula crosses the sphincter muscles (see section on More about anal or perianal fistulas), the procedure allows any abscesses to be drained or setons to be put in place (see Surgery).
To see where the fistula is in relation to the sphincter muscles, you may have the following tests:
Often, a combination of all these techniques is used to fully assess a fistula.
In addition to MRI, ultrasound and fistulography, a blue dye test can be used. This is where the doctor inserts a tampon into the vagina and blue dye into the rectum. If the tampon stains blue, this shows that there is a connection.
Using a long thin telescope with a camera (cystoscope), doctors can look inside the bladder and the tube carrying pee from the bladder (urethra). They may carry out the ‘poppy seed test’. Here, the person eats poppy seeds which remain undigested in the bowel with yoghurt. If the seeds appear in the pee this shows that there is a bowel to bladder connection.
Your IBD team should explain the treatment choices available to you and the pros and cons for each. Ask as many questions as you need to. Our Guide to Appointments can help you to make decisions about your care and treatment together with your IBD team.
Continuing your usual treatment for Crohn’s or Colitis often helps, as active disease tends to make fistulas worse. But your doctor may recommend avoiding steroids as these can increase the chance of developing an infection or abscess and the need for surgery.
In this section:
Treatment aims to get a balance between healing the fistula and keeping control over your bowels.
Up to 1 in 3 people with Crohn’s who have an anal fistula will need an operation at some time. The goal of surgery is to heal the fistula while avoiding damage to the anal sphincter muscles. These muscles surround the anus and control the release of poo.
The type of surgery you’re offered will depend on:
If you have any abscesses, these will be drained before surgery.
Loose setons are soft surgical threads. The surgeon passes these through the opening in the skin, along the track of the fistula and out through the anus. It’s then tied to form a loop. The ends hang out of your anus, allowing the pus or infected tissue to drain away. The seton is usually left in for several weeks and removed if the fistula is healing. Studies show that adding loose setons to infliximab treatment leads to better results for people with anal fistulas. Some people say that a loose seton feels like having a rubber band hanging out of your bottom, but after a few days they no longer notice it’s there. In some cases, setons are used as a long term treatment if fistula healing is unlikely.
It is quite embarrassing to tell someone that I have a little rubber band coming out of my bum (a seton). But I only tell people I trust and feel comfortable with, and they have been really supportive.
Finlay
Living with Crohn's
This is the most common type of operation for anal fistulas and the most effective for many. In this operation the length of the fistula is cut open, much like cutting open a cardboard tube along its length and flattening it out. This promotes healing from the base of the fistula to the surface. Healing may take from a week to several months.
This procedure is only suitable for simple fistulas that either don’t cross the sphincter muscle at all or only pass through a small amount. Advancement flaps, LIFT and VAAFT will only be used in selected people and only after counselling as long-term results are poor, particularly for people with complex disease and ongoing disease activity.
I had day surgery for an anal fistula. I was anxious before the operation as I had never had a general anaesthetic before, and the surgeon couldn’t say whether he would be able to lay it open or if I would need a seton stitch. In the end it went very smoothly and he was able to lay it open. Having the operation has made such a difference. I started to feel the benefits quickly afterwards and the relief was immense.
Lucy, 45
Living with Crohn's
After the fistula track has been cleaned, leaving sphincter muscles intact, the inside lining of the rectum is lifted and pulled down inside the anal canal to cover the internal opening of the fistula. This operation is used for complex fistulas where the sphincter muscles are involved and where cutting the fistula track open would carry a high risk of losing bowel control.
This operation aims to avoid cutting the sphincter muscle. The surgeon gains access to the space between the internal and external anal sphincter muscles through a small cut at the entrance to the anal canal. Once the surgeon has found the fistula tunnel crossing this space, it is cut in two. Both ends are then stitched closed to stop poo getting into the fistula.
Using a telescope, the technique allows the doctor to see the fistula track from inside. After cleaning, the fistula can be sealed using an electric current to close the track. Stitches and fibrin glue can also be used. This technique may help surgeons find extra passages running off the main fistula, which need treatment for the fistula to heal.
Like any treatment, surgery for anal fistulas has some risks. The main ones are:
Research funded by Crohn's & Colitis UK found that asking your healthcare professional about the following topics can help you make an informed decision about surgery for an anal fistula:
Other treatments for anal fistulas include trying to close the fistula with fibrin glue, a bioprosthetic plug (using materials such as Gore-Tex®), or collagen paste, or sealing the fistula tract with a laser probe.
If you have a fistula which involves the bladder or vagina, a specialist from the Urology or Gynaecology departments, as well as your IBD team may assess this. Ask your consultant to arrange this.
Treatment can include:
Surgery aims to remove the affected bowel, join up the healthy bowel and close the hole in bladder wall. This may be carried out in stages. A recent study showed that many people undergoing surgery for bowel to bladder fistulas maintained remission for over eight years.
Medicines aim to treat the underlying active Crohn’s or Colitis with antibiotics, immunosuppressants and infliximab.
Operations for vaginal fistulas include:
A surgeon who has specialised in this type of complex and difficult operation will usually perform these.
The aim of surgery is to remove the affected bowel, join up the healthy bowel, and close the fistula opening on the abdominal wall.
For bowel to bowel and bowel to skin fistulas, biologics, such as infliximab, may help to heal the fistula or improve symptoms.
If surgery is needed with bowel to bowel fistulas, the diseased bowel is removed, and the fistula opening in the healthy bowel is stitched. For bowel to skin fistulas, the fistula may close on its own. But if the fistula stays open for longer than two months this isn’t likely and surgery may be considered.
Some people with these types of fistulas may not absorb adequate nutrients from their food or may lose nutrients through the opening in the skin. This can be treated through a special liquid only diet with all the necessary nutrients or by an infusion of nutrients directly into a vein. Find out more in Food.
For bowel to skin fistulas, your body fluid levels and electrolytes (levels of sodium, potassium, magnesium, and chloride in the blood) are regularly monitored and corrected to replace any losses. If the fistula opens onto your skin, a drainage bag can be positioned over the area where the fistula opens to collect any discharge. Your skin will need to be protected from the irritant effects of the gut contents as these can injure the skin.
Surgery for bowel to skin fistulas can be difficult. It may be affected by factors such as the position of the fistula and how active your Crohn’s or Colitis is. The aim of surgery is to remove the affected bowel, join up the healthy bowel, and close the fistula opening on the abdominal wall. People with bowel to skin fistulas may need to stay in hospital for long periods.
Unfortunately, none of these ways of closing fistulas is guaranteed to be successful. Multiple or repeat operations may be needed. Some people continue to have problems with fistulas even when Crohn’s is in remission. Sometimes a fistula that isn’t painful may remain, but this may still leak and need ongoing care.
Where treatment has not worked for anal fistulas, a small number of people may have an operation to remove the rectum to allow the fistula to heal. The gut is brought to the surface of the abdomen as a stoma so that waste can be collected outside the body in a bag. Find out more in Surgery for Crohn’s Disease.
If you’ve had an operation for your fistula, the hospital staff will show you how to do your dressings. When you get home a district nurse may visit to do the dressing for you. Depending on the type of fistula, you may soon find that you can manage this yourself.
You’ll have regular reviews to check that the fistula is healing properly. Your IBD team, especially your IBD nurse, will be able to help with practical advice. Your GP and the practice nurse may also be a good source of information about day-to-day care of your fistula. Talk to your team about the best ways to:
Ask your nurse or doctor about the different types of dressing available. You can get many of these on prescription. If you have a permanent fistula that needs on-going surgical dressings, you can be issued with a ‘Medical Exemption Certificate’ to get free NHS prescriptions. Talk to your IBD team or GP to find out whether you are eligible.
I found using fragrance free toilet wipes and using a hairdryer on a very low heat to gently dry my bottom, helped me to prevent getting an infection in the anal fistula I had.
Lucy
Living with Crohn's
The sitz bath was the easiest, least painful and most effective way for cleaning myself after a toilet motion.
William
Living with Crohn's
I have a stoma and peri-anal drains due to fistulas. These drains produce liquid, so I make sure I always carry lots of useful things to help with this, including swabs and wipes. I find this little bag of ‘stuff’ keeps me calm, knowing I have it with me.
Gillian
Living with Crohn's
This is a medical emergency. Sepsis can be hard to spot but if you think you have symptoms call 999 or go to A&E.
Don’t be afraid to ask for help. Your IBD team should be able arrange for you to see a psychologist or counsellor. This can help you to feel more in control and able to cope better with living with a fistula see Mental health and wellbeing.
It may help to remember that having a fistula is not uncommon and that they also occur in people who don’t have Crohn’s or Colitis. For most people, living with a fistula becomes much more manageable once they get used to the care their condition needs.
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