Balloon dilatation of strictures in Crohn's disease

What a stricture is

Crohn's disease inflames the full thickness of the bowel wall, not only its lining. More than half of people with Crohn's disease develop a stricture or a fistula within ten years of diagnosis. When inflammation goes on for long enough, the body repairs it with scar tissue, and scar tissue contracts. The result is a segment of bowel that is narrower and stiffer than it should be. This is called stricturing, or fibrostenosing, Crohn's disease. The end of the small bowel, the terminal ileum, is the most common place for it.

Strictures also form at the join left by previous bowel surgery, called an anastomosis, where Crohn's disease often comes back. These anastomotic strictures are among the most suitable for balloon dilatation.

Most strictures are a mixture of two things: active inflammation, which swells the wall and can respond to medicines, and established scarring, which does not. Working out how much of each is present decides what treatment makes sense.

What are the symptoms of a stricture

A narrowing makes it hard for food and fluid to pass. Typical symptoms are:

• crampy abdominal pain, often 30 minutes to a few hours after eating
• bloating, a gurgling or audible bowel and a feeling of fullness
• nausea and vomiting
• eating less to avoid the pain and losing weight as a result

Complete blockage of the bowel, with constant pain, repeated vomiting and no wind or bowel motions, is an emergency and needs assessment in an emergency department the same day.

How a stricture is assessed

Before any treatment is chosen, the stricture needs to be understood: where it is, how long, how tight, whether it is mostly inflamed or mostly scarred and whether there is a fistula or abscess nearby. That usually takes more than one test.

• MRI enterography, an MRI of the small bowel after a drink that distends it, shows the length and number of strictures, the bowel above them and any fistula or abscess.
• Intestinal ultrasound, done in the clinic, shows the thickness and blood flow of the bowel wall and can be repeated to see how a stricture responds to treatment.
• Colonoscopy shows strictures within reach of the scope directly, and allows biopsies. Any stricture in the colon is biopsied, because although most are due to Crohn's disease, a narrowing can occasionally hide a cancer.
• Blood tests and faecal calprotectin help show how much active inflammation there is.

What are the treatment options

There is no single right answer for every stricture, and the options are often combined.

• Medical treatment. Where a stricture is mainly inflamed, treating the inflammation with biologic or other therapy can ease the narrowing without any procedure. Controlling inflammation also matters after a dilatation or an operation, to slow the process down.
• Nutritional therapy. Exclusive enteral nutrition, a period of liquid formula in place of normal food, can settle inflammation and improve symptoms in stricturing disease and is used before surgery to reduce complications.
• Balloon dilatation, for strictures the endoscope can reach. Shorter strictures respond best, and longer strictures, or those with a fistula nearby, can also be dilated in selected cases.
• Surgery, either removing the narrowed segment or widening it without removing bowel (strictureplasty). Surgery remains the right choice for some people, for example when cancer cannot be excluded, when there are several strictures or complications that cannot be managed endoscopically or when dilatation has stopped working. Care is shared with colorectal surgeons, and the decision is made together.

Stricture care is part of the wider management of Crohn's disease and ulcerative colitis.

Who balloon dilatation suits

Dilatation is considered for strictures that are:

• within reach of a colonoscope or gastroscope, such as the terminal ileum, the join after previous surgery, the colon or the oesophagus
• not suspicious for cancer

Short strictures, around 5 cm or less, respond best. Longer strictures, and those with a fistula nearby, can also be dilated in selected cases. The decision depends on the whole picture from the scans and colonoscopy.

Shorter strictures have the most evidence behind them. In a pooled analysis of individual patient data, a stricture of 5 cm or less was associated with avoiding surgery, and each additional centimetre of length increased the chance of needing an operation by about 8 per cent. Evidence is now growing that longer strictures, and strictures with complications such as a fistula or abscess, can also be managed endoscopically in selected patients.

Stretching a narrowing and treating the inflammation that caused it are usually done together, because each addresses something the other cannot. Whether the combination produces better results than either alone is a different question, and an open one. The published work so far does not settle it, and some of it points the other way: in an international cohort of 57 people with ileal strictures, those who had been dilated in the six months before starting a biologic went on to need more procedures rather than fewer. The IBD group at Concord Hospital is working on how these strictures are best managed, and A/Prof Kariyawasam's own study of a combined pathway is described below.

How it is done

Dilatation is done during a colonoscopy for strictures of the ileum and colon or a gastroscopy for the oesophagus, under sedation given by a specialist anaesthetist. Preparation is the same as for the ordinary procedure.

Once the stricture is reached, a deflated balloon is passed through the scope into the narrowing and slowly inflated with water to a set diameter, held for a short time and then deflated. The diameter is chosen for the stricture and increased gradually rather than stretched in one step.

Most people go home the same day, after a period of observation. Some are kept in overnight.

If you take a blood thinner, the plan for the days around the procedure is worked out with the endoscopist beforehand, because it depends on which medicine it is and why you are on it. Low-dose aspirin is the one that is usually continued. Never stop a blood thinner on your own.

What the evidence shows

The largest pooled analysis brought together 1,463 people with Crohn's disease who had 3,213 dilatations, almost all of them in the ileum and most at a previous surgical join. The balloon could be passed and inflated in 89 per cent of procedures, and symptoms improved in 81 per cent.

The improvement is not always permanent. Over two years of follow-up, about three in four people had a further dilatation, and about four in ten went on to surgery. For many people the realistic aim is to control symptoms and put off or avoid an operation, with repeat dilatation when needed, alongside treatment of the underlying inflammation.

Australian results are similar, and they are among the largest published anywhere. A study across 12 hospitals in Australia and New Zealand, including Concord, Liverpool and St Vincent's in Sydney, covered 273 people with stricturing Crohn's disease who had 695 dilatations between 1999 and 2019. The stricture was successfully passed with the colonoscope afterwards in 83 per cent of procedures. Four out of five of the strictures treated were shorter than 4 cm, and long strictures failed significantly more often. Over a median follow-up of close to four years, 27 per cent needed surgery within five years, and the length of the stricture was the only factor that predicted it.

Complications were rare: five in 695 dilatations, or 0.7 per cent. Three were perforations and two were aspiration. There was no major bleeding and nobody died as a result of the procedure. The authors' conclusion is worth quoting for what it does and does not claim: dilatation is a highly effective and safe procedure in both new and anastomotic strictures shorter than 4 cm, and it can prevent or delay the need for surgery.

For strictures deeper in the small bowel, reached with a longer, specialised enteroscope, pooled results show similar short-term success, with about one in four people proceeding to surgery during follow-up. A Sydney series from Macquarie University Hospital, in which MRI enterography was used to find and map the strictures first, reached 19 of 20 strictures, and none of the ten patients needed surgery over the following year.

What are the risks

Major complications occurred in about 2.8 per cent of dilatations in the largest pooled analysis. The most important is a tear (perforation) of the bowel wall, which may need an operation to repair. Bleeding can also occur and usually settles by itself. Risks are higher when inflammation is severe or the stricture is long or angulated, which is part of why careful selection matters.

Some abdominal discomfort and bloating is common for a few hours. Severe or worsening abdominal pain, fever, vomiting, chest pain after an oesophageal dilatation or significant bleeding in the days afterwards need urgent assessment. Contact the rooms or the hospital, and if it is severe, go to an emergency department.

Strictures of the oesophagus

Balloon dilatation is also used for narrowings of the oesophagus that cause food to stick. The common causes are long-standing reflux, rings and webs, eosinophilic oesophagitis and scarring after surgery or radiotherapy. The dilatation is done at gastroscopy, and if food has become stuck it can be removed at the same time.

As in the bowel, stretching treats the narrowing but not its cause. Acid suppression for a reflux stricture, or specific treatment for eosinophilic oesophagitis, is what reduces the chance of it coming back. Biopsies are taken where appropriate.

Research in stricturing Crohn's disease

Strictures remain the leading reason for surgery in Crohn's disease. In a Sydney cohort of 972 people with Crohn's disease followed over four decades, to which A/Prof Kariyawasam contributed, the risk of major abdominal surgery was about 32 per cent within five years of diagnosis and 48 per cent within 15 years, and stricture or obstruction was the main reason for it.

A current line of work asks whether treatments used together do better than any one of them alone. A/Prof Kariyawasam is the senior author of a study of adults with stricturing Crohn's disease, and Crohn's disease with both stricturing and penetrating features, managed on a single integrated pathway. The pathway combined enteral nutrition, exclusive or partial and supervised with a dietitian, starting or optimising a biologic, a short course of corticosteroids where it was needed and balloon dilatation where the stricture warranted it. Patients treated between 2019 and 2023 were followed to 2025, and the study looks at how many avoided surgery and what happened to their symptoms, blood markers and imaging over that time. It is not yet published. The findings will be added here once it is.

Why some people develop scarring and strictures while others do not, how imaging and biomarkers might predict it earlier and how endoscopic treatment can be extended to more complex strictures are focuses of the Concord and Macquarie IBD research group, which A/Prof Kariyawasam is part of.

Where balloon dilatation is performed in Sydney

A/Prof Viraj Kariyawasam is a consultant gastroenterologist and hepatologist whose practice is focused on inflammatory bowel disease, including stricturing Crohn's disease. Assessment is at consultation in Norwest, Rouse Hill, Pennant Hills and Macquarie Park.

The dilatation is performed during a colonoscopy at Norwest Private Hospital, Macquarie University Hospital and Pennant Hills Day Surgery. A referral from your GP is needed for a consultation.