Bowel cancer, or colorectal cancer, is currently the second deadliest and fourth most common newly diagnosed cancer in Australia – and it’s rapidly increasing among young people.
This sharp and sudden rise has prompted researchers to explore potential factors that might raise a person’s risk of developing bowel cancer – and one of these findings highlights a connection with another health condition.
Inflammatory Bowel Disease (IBD), such as ulcerative colitis and Crohn’s disease, is associated with an increased risk of bowel cancer due to chronic inflammation of the intestinal lining.
Research has shown that people living with IBD have a three to five times higher risk of developing colorectal cancer compared to the general population.
This interaction between IBD and colorectal cancer is critical information for clinical experts like Australian gastroenterologist Dr Réme Mountifield.
The Associate Professor at Flinders University and gastroenterologist who specialises in Inflammatory Bowel Disease told Daily Mail that uncovering this connection is crucial to bowel cancer prevention amongst more susceptible IBD sufferers.
She explained that although there has always been awareness about an increased risk of bowel cancer among people with IBD, the latest research suggests this risk has grown.
‘People with inflammatory bowel disease probably have about double the risk of contracting bowel cancer compared with the general population,’ Dr Mountifield said.
There has been increased public awareness of the rise of colorectal cancer amongst young people. Hollywood actor James Van Der Beek announced his stage 3 colorectal cancer diagnosis in November 2024 and passed away from the disease this February at the age of 48
Bowel cancer can cause you to have blood in your poo or a change in bowel habit, along with other symptoms
‘We’ve known for a long time that an abnormal bowel tends towards those genetic sequence changes that then become pre-cancerous and cancerous, whereas a normal bowel is less likely to do so.’
The expert notes that, like bowel cancer, the incidence of IBD is also on the rise. However, she says it’s an oversimplification to suggest this is the sole reason for the overall rise in colorectal cancers, particularly among young people.
‘We know that both are increasing, but IBD does not account for all of that increase.
‘There’s currently a lot of research looking at the rise of colorectal cancer, examining diet, lifestyle and migration studies to determine if it’s due to environmental or genetic factors. We think it’s a combination, but it may well be related to diet.’
‘So the advice for young people concerned about colorectal cancer – whether you’ve got IBD or not – is really about looking at your diet, maintaining a healthy lifestyle, not smoking, consuming alcohol safely, undertaking 30 minutes of exercise five times a week, and following a balanced diet that reduces ultra-processed food and processed red meat and emphasises fibre, fruit and vegetables, legumes, oily fish, and dairy in moderation.’
Understanding IBD and its main tell-tale symptoms
Dr Réme Mountifield, a gastroenterologist who specialises in Inflammatory Bowel Disease, confirmed an increased risk of bowel cancer amongst IBD sufferers.
Inflammatory bowel disease is a catch-all term for two conditions: ulcerative colitis and Crohn’s disease.
‘They both occur because of an inappropriate autoimmune attack on different parts of the bowel, so the immune system is overactive,’ explains Dr Mountifield.
The first signs of IBD a person may experience include red flag symptoms like ‘bleeding from the bowel’, but also more subtle and non-specific symptoms such as ‘diarrhoea or urgency, meaning that sudden need to rush to the bathroom’.
‘People can also get pain, bloating, nausea and vomiting. There might be bowel obstructions present as well.’
The symptoms experienced can vary as they’re dependent on where the autoimmune, inflammatory attack on the bowel is located.
IBS versus IBD – and the completely different playing field
An unsettled tummy or bouts of discomfort in the bathroom is something many people experience from time to time, but particularly those who suffer from irritable bowel syndrome (IBS).
Dr Mountifield explains: ‘A lot of people have gastrointestinal symptoms. We know that 40 per cent of the population have irritable bowel syndrome (IBS).’
However, the expert stresses that, although IBS and IBD can share common symptoms like ‘pain, bloating and diarrhoea’, they are ‘not the same’.
‘When we have a look inside the colon of someone with IBD, using a colonoscope for example, we see inflammation. We see ulcers and blood and it doesn’t look normal.’
Dr Mountifield highlighted that although IBS and IBD can share common symptoms like ‘pain, bloating and diarrhoea’, they are ‘not the same’. She noted that IBS does not increase the risk of contracting bowel cancer
‘The difference with irritable bowel syndrome is that although the symptoms can be really disabling, those symptoms don’t shorten your lifespan.
‘IBS also doesn’t increase your risk of bowel cancer. It doesn’t require medication that reduces the immune system, and it doesn’t need surgery.’
IBD symptoms to lookout for
Gastrointestinal discomfort is usually just the tip of the iceberg for IBD sufferers – and that’s one area that makes it distinct from IBS.
‘One of the main symptoms we look out for is bleeding from the bowel,’ says the gastroenterologist.
Other symptoms include weight loss, loss of appetite, and sudden changes in bowel habits.
She explained that people with IBS tend to experience fluctuating bowel movement and discomfort issues from an early age, and that these continuously reoccur.
IBD sufferers, on the other hand, tend to experience a sudden change in bowel habits at the onset of inflammation, becoming either ‘more constipated or experiencing diarrhoea, bleeding, weight loss, loss of appetite and, in particular, an increase in pain.’
‘A change is what people should be on the lookout for, and if they have any concerns, it can be easily investigated, starting with the GP.’
Your doctor should be the first port of call when any of these symptoms arise. They can order a range of tests, from stool sample assessments to a full colonoscopy.
‘Don’t ignore the warning signs. If you think you’re at risk, or something has changed with your bowel habit, or you have bleeding, you must seek attention.’
IBD treatment options
IBD is an immune attack on the bowel, with Dr Mountifield explaining that treatment options range from medical to surgical treatments.
‘We generally start by using medications that reduce the action of the immune system, targeting different components to dampen the immune response.’
There’s a wide range of options – from oral tablets to injections and infusions – all intended to suppress the immune system and, hopefully, reduce the need for surgery.
In instances where surgery is necessary, it may see some patients ‘have their whole colon removed, or parts of their small bowel’.
‘We do try to reduce the need for that by trying medical therapy first, but sometimes when people are diagnosed late, or they have strictures or blockages of the bowel, surgical management is needed, and sometimes for disease around the bottom, that’s perianal disease.’
People with inflammatory bowel disease (IBD), such as Crohn’s and ulcerative colitis, are known to have an increased chance of developing bowel cancer
Mitigating the risk of colorectal cancer amongst IBD sufferers
There are two IBD management elements that also help reduce the increased risk of bowel cancer.
The first is ensuring patients are on an effective medication plan that allows for ‘really tight control of inflammation’.
‘We know there’s an increased risk of bowel cancer in people with IBD, but it’s really lowered and mitigated by using these medications that control inflammation, because in these patients, inflammation is the driver of cancer development,’ Dr Mountifield says.
This is then accompanied by consistent and vigilant monitoring by looking inside the bowels and performing biopsies.
‘If it all looks normal, we lower that risk of bowel cancer enormously.’
Act on bowel movement concerns as a matter of urgency
Worrying gastrointestinal symptoms such as those described should not be ignored – with Dr Mountifield urging anyone with even mild conditions to follow up with their doctor.
‘When we diagnose bowel cancer early, the outcome or prognosis is excellent. If we diagnose it late, it’s a very different situation. I would encourage people to not ignore symptoms.
‘Often, it will not be cancer; it will be something else. And, for example, if it does turn out to be IBD because you have blood in the bowel, it’s really important that we diagnose that early too.
‘IBD is quite often diagnosed late. But the earlier it’s diagnosed, the earlier we can start on those really effective treatments – and that in turn reduces the risk of bowel cancer along with any other undesirable health outcomes.’
