Can IBS cause Colon Cancer?

We all have had uncomfortable experiences in the bathroom before. Constipation, diarrhoea, and bloating are all common occurrences. However, when these signs happen frequently over a long period of time, they can become a condition known as irritable bowel syndrome (IBS). While this is not life-threatening, could it manifest into something more serious like colon cancer?  

 If you have IBS and are worried about the consequences of this diagnosis, read on to find out more about the difference between IBS and colon cancer, and whether one can lead to the other.   

Understanding IBS and Its Impact on Digestive Health 

Irritable Bowel Syndrome (IBS) is a chronic condition that affects the digestive system, mainly the large intestines (also known as the colon). IBS is characterised by a range of symptoms such as:   

  • Constipation, diarrhoea, or alternating of both  
  • Feeling of incomplete bowel movements 
  • Indigestion 
  • Abdominal pain  
  • Bloating  
  • Whitish mucus in the stool  

There is no exact cause for IBS, though it is associated with food intolerance, eating too fast, gastroparesis (reduced movement of the digestive tract), and infection. Certain medications like antibiotics, and sorbitol (a type of sugar)-based medicine e.g. cough syrup is linked to IBS. IBS is also a classic example of how the mind affects the body – it is commonly seen among people with anxiety, depression, or chronic stress.  

Across the world, more than 11% of people have IBS. In Singapore, almost one in 10 people experienced IBS before. It can happen to anyone, though it tends to affect more women than men, and is more frequent among those in their 30s and 40s. Thankfully, IBS is not life-threatening, and it does not cause any structural damage to your digestive organs. Nonetheless, the recurring symptoms undoubtedly compromise one’s quality of life.  

Can IBS Cause Colon Cancer? 

While IBS does not cause any structural damage to the digestive system, cancer does. Colorectal cancer is characterised by the abnormal growth of cells in the colon or rectum, eventually forming polyps (non-cancerous) that can turn into cancerous tumours. In this case, the tumour causes tissue damage and obstruction to the digestive tract. While colorectal cancer shares similar symptoms with IBS, it is a more serious condition that comes with more alarming signs such as:  

  • Unexplained weight loss 
  • Blood in stool / rectal bleeding 
  • Narrowing of the stool, indicative of something blocking the colon  
  • Fatigue 
  • Inflammation  

While the signs of IBS may look similar to colorectal cancer, there is no direct association between the 2. As colorectal cancer has a long generation time (5-10 years), there should be an increased number of cancer cases among IBS patients over the years if the 2 are linked. However, a study in Denmark followed patients with IBS for 10 years and found that there was no increased risk of colorectal cancer cases among these patients. A larger study found that there is an increased risk of colorectal cancer among patients with IBS in the first year, though it declined over time. This is likely due to diagnostic error as the symptoms between IBS and colorectal cancer can look very similar, especially in the early stages.  

Hence, despite their overlapping symptoms, IBS does not increase the risk of colorectal cancer. These 2 conditions are based on very different mechanisms, with the former being relatively manageable through lifestyle changes, while the latter requiring medical intervention. Nonetheless, the early warning signs of colorectal cancer can sometimes be mistaken for IBS. It is important to go for a more diagnostic screening to confirm whether your symptoms are due to IBS or something more serious.  

Importance of Colon Screening 

Colorectal cancer is one of the most common cancers in Singapore, with more than 1,500 cases diagnosed per year. Due to the overlapping symptoms, colorectal cancer can be mistaken for IBS, and unique signs of cancer typically do not usually till the later stages. Hence, regular colon screening is crucial in detecting and treating any anomaly before it manifests.  

Colon screening involves colonoscopy, which involves the insertion of a colonoscope via the anus to view the inside of the rectum and colon to check for signs of tumour growth. During the process, any pre-cancerous polyps will also be removed, preventing them from developing into cancerous tumours in the body. This procedure, around one hour, is performed under sedation, hence you should feel little to no discomfort. A small tissue sample may be extracted for further testing. Other screening methods like CT scans may be used as well. Blood and stool tests may be required to eliminate other conditions like infection or genetic diseases e.g. celiac disease.   

At the Centre for Screening & Surgery,  our medical team brings years of experience under their belt to guide you through the screening process. It is important to voice out any concerns that you may have so they can make the screening process as comfortable as possible for you.  

When Should I Seek Medical Attention? 

If you notice any symptoms like diarrhoea, constipation, cramps, bloating, rectal bleeding, and/or unexplained weight loss that is persistent, seek medical attention immediately.  

Do not self-diagnose or assume things about your symptoms. Some overlapping signs and symptoms need to be assessed by medical professionals so that the treatment is personalised for your healthcare needs.  

Lifestyle Changes and Risk Management  

While there is no solution to 100% eliminate the risk of IBS or colorectal cancer, there are steps that you can take to not just reduce the risk but also to improve your digestive health: 


Dietary changes 

Avoid excessive consumption of highly processed and fatty foods and keep your caffeine intake to a maximum of 3 cups per day. For people with IBS with constipation (IBS-C), swap out refined grains for whole grains, fruits, and vegetables. Make sure your fibre intake is about 25g for women and 38g for men. Don’t skip any meals and try to eat at the same time each day to regulate your bowel movement.  

For people with IBS with diarrhoea (IBS-D), food intolerance to dairy and gluten is a common cause. Hence, you should seek out a professional to understand the types of food you are sensitive to. Avoid dairy products for those with lactose intolerance. If you have gluten intolerance, opt for wheat-based foods instead.  


Stress Management 

IBS is often linked to anxiety, depression, and chronic stress. While work or family commitments can seem endless, we all deserve a break once in a while. Dedicate time off your week to fully focus on yourself and do something that you enjoy.  

Try to get at least 7 hours of sleep per day and 150 minutes of exercise per week. Studies have shown that a good sleep and sweat session releases endorphins, which reduces stress. These activities are also crucial in building your physical health to be better prepared against other diseases.  



Certain antibiotics and antidepressants may trigger IBS. Speak to your doctor first before discontinuing or switching your medication.   

If you are experiencing constipation, over-the-counter laxatives will stimulate gut mobility to relieve some of your discomfort. For women, IBS symptoms may feel worse during your period. Taking some painkillers or hormonal pills may be helpful. However, talk to your doctor about whether you are suitable for this treatment first. 



IBS and colorectal cancer share many similar symptoms like indigestion, diarrhoea, constipation, bloating and more. However, having IBS does not increase your risk of colorectal cancer, which is more commonly associated with genetics, age, and other lifestyle factors.  

However, with such overlapping symptoms, IBS can potentially mask the warning signs of colorectal cancer. Hence, it is important to schedule a colon screening regularly to check for tumour growth, especially if you have IBS and/or experience rectal bleeding or unexplained weight loss.  

Health is our main asset, and it is our responsibility to protect it. Other than regular screening, modifiable risk factors like managing your stress and dietary intake will go a long way towards building longevity and good health.  


Protect Your Health Today 

If you are experiencing IBS symptoms, or suspect you may have colorectal cancer, feel free to visit us at the Centre for Screening and Surgery. Our clinic specializes incancer screeningand treatment of cancers at an early stage with minimally invasive procedures. Call us to book an appointment today! 


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