Irritable Bowel Syndrome and Colon Cancer- Is there a Connection?

Published on Monday, October 17, 2022 by Emily Hamm

It is no fun to think this way, but I am sure a lot of you irritable bowel syndrome (IBS) sufferers have wondered… will I one day get colon cancer?

After all, it is a valid concern and worry especially with cancer on the rise as a leading cause of death among western populations.

You’re not alone in this thought… I often think to myself anytime I feel weird… “oh no I have cancer?” (I do work with cancer patients daily- so maybe it’s also because it is all I think about 40 hours a week). To help ease your mind let us look at what research has to say about this topic and discuss ways to optimize your health and reduce your risk of developing cancer.

As discussed in other articles on our website, IBS causes chronic inflammation in the gut. Chronic inflammation has been linked to the development of cancer so it is plausible to argue IBS could lead to cancer. To date, there are limited large, long-term, longitudinal studies (studying a large group of people over time) to evaluate associations between IBS, overall cancer risk, site-specific cancer risk, and cancer-specific mortality.

Recently a meta-analysis was conducted to identify if there were any associations found in current literature to link IBS to the risk of colorectal cancer. They identified 6 studies with over 1 million subjects combined. Overall, they found that the risk of developing colorectal cancer was highest within the first year of the initial IBS diagnosis but no significant risk increased long-term after an IBS diagnosis.

They suspect that this increased risk within the first year was due to misclassification or misdiagnosis in these subjects- IBS and colorectal cancer have similar presenting symptoms (changes in bowel habits, bloating, abdominal pain, etc.). They did note that IBS subjects under the age of 50 had a higher chance of developing colon cancer vs their counterparts, suggesting that routine screening for cancer is important.

In a recent longitudinal study conducted in the UK with almost 500,000 participants (~22,000 participants were diagnosed with IBS), there was no notable increase in the overall risk of cancer among IBS sufferers compared to the general population. Instead, they noted an associated lower risk of colorectal cancer.

In regards to irritable bowel disease (IBD- think colitis, Crohn's disease, celiac, etc.), there has been research to suggest a higher incidence of colorectal cancer later in life. There are several grounds of thought on this which we will discuss in a future article- the “common ground hypothesis”.

Bottom line: If you have developed IBS-like symptoms, follow up with your medical provider. Advocate for yourself and if you have been diagnosed with IBS, talk with a registered dietitian to find ways to limit trigger foods. You may need to follow a Low FODMAP diet.

To reduce overall cancer risk follow these key points as defined by the American Institute for Cancer Research:

Maintain a healthy weight- if you are struggling to achieve a healthy weight, work with a dietitian to help meet this goal
Get active – find ways to move and exercise- aim for 30 minutes of moderate physical activity 5 days a week
Eat a diet rich in plant foods- if you suffer from IBS, talk with a dietitian to figure out what plant foods are best for you to manage your symptoms
Limit your consumption of fast food and other processed foods that are high in added sugars and fat
Limit consumption of red meat and processed meat
Limit consumption of sugar-sweetened beverages- choose mainly water
Limit alcohol consumption

_{Scoring WCRF/AICR Cancer Prevention Recommendations | EGRP/DCCPS/NCI/NIH. (n.d.). Retrieved September 30, 2022, from https://epi.grants.cancer.gov/wcrf-aicr-score/}
_{Wu, S., Yuan, C., Liu, S., Zhang, Q., Yang, Z., Sun, F., Zhan, S., Zhu, S., & Zhang, S. (2022). Irritable Bowel Syndrome and Long-Term Risk of Cancer: A Prospective Cohort Study Among 0.5 Million Adults in UK Biobank. The American journal of gastroenterology, 117(5), 785–793. https://doi.org/10.14309/ajg.0000000000001674}
_{Wu, X., Wang, J., Ye, Z., Wang, J., Liao, X., Liv, M., & Svn, Z. (2022). Risk of Colorectal Cancer in Patients With Irritable Bowel Syndrome: A Meta-Analysis of Population-Based Observational Studies. Frontiers in medicine, 9, 819122. https://doi.org/10.3389/fmed.2022.819122}