Does Anal Sex Increase the Risk of Colon Cancer? 

Introduction

Many people wonder if anal sex can lead to colon cancer. Currently, anal sex itself is not considered a direct cause of colon cancer¹. However, certain infections from anal intercourse may affect the anal area and increase the risk of anal cancer². In this article, we will discuss colon cancer, whether it is associated with anal sex, risk factors for colon cancer, symptoms that shouldn’t be ignored, and when to seek medical attention. 

What Is Colon Cancer?

Colon cancer is a type of cancer that starts in the colon, which is the longest part of the large intestine. It usually begins when colon cells grow and divide unusually, forming a small growth called a polyp. Some polyps are harmless, while others may gradually develop into cancer over time. Colon cancer specifically affects the colon, while rectal cancer starts in the rectum, the final part of the large intestine. When cancer affects either the colon or rectum, it can be called colorectal cancer³.

Does Anal Sex Cause Colon Cancer?

Anal sex is not an established direct cause of colon cancer. Current evidence does not show that having anal sex causes cancer to develop in the colon¹. Colon cancer usually develops because of changes in the cells of the colon and is influenced by factors such as age, family history, lifestyle, and certain medical conditions⁴. Therefore, anal sex should not be considered a direct cause of colon cancer. 

Anal Sex and Colon Cancer: What Is the Role of HPV?

Human papillomavirus (HPV) is a very common virus that can spread through intimate skin-to-skin contact, including sexual contact (vaginal, anal or oral sex)⁵. Some types of HPV can cause changes in cells that may eventually lead to cancer. HPV is strongly linked to anal cancer, which begins in the tissues around or inside the anus². 

However, anal cancer and colon cancer are different diseases because they develop in different parts of the digestive tract. A link between HPV and anal cancer does not mean that HPV or anal sex directly causes colon cancer¹. Although some studies have found a possible link between HPV infection and colorectal cancer, more research is needed to confirm whether HPV directly contributes to its development⁶.

What Really Increases the Risk of Colon Cancer?

Several factors can increase the risk of colon cancer. These include: 

• Age: The risk of colon cancer tends to increase with age (especially in people over 45 years old). 
• Family History: If a close family member has had colon cancer or certain types of bowel polyps, the risk of colon cancer may be high⁴. 
• Sex: Men are more likely to have colon cancer than women. 
• Polyps/Polyposis Syndrome: Having certain types of polyps in the colon can increase the chance of developing cancer later. 
• Radiation Therapy: Previous radiation exposure, as a part of an earlier cancer treatment (near the colon), can increase the risk of colon cancer. 
• Unhealthy Diet: A diet high in processed meat and red meat and low in fibre may increase colon cancer risk. 
• Smoking: Smoking is known to increase the risk of colon cancer and may increase the occurrence of colon polyps compared to non-smokers. 
• Alcohol: Alcohol consumption, even in moderate amounts, is known to increase the risk of colon cancer⁷. 
• Low Physical Activity: Spending most of your time sitting and doing little physical activity may increase your risk⁴. 
• Inflammatory Bowel Disease (IBD): Long-term inflammatory conditions, such as ulcerative colitis and Crohn’s disease, can increase the risk. 
• Obesity: Being obese or excess body weight can increase the risk (especially in men). 
• Diabetes: According to some researchers, type 2 diabetes is known to increase the risk of colon cancer, especially due to high amounts of insulin in the body and shared risk factors like obesity and physical inactivity⁷.

Note: Having one or two risk factors doesn’t mean that you’ll get colon cancer, and one can get colon cancer even if one does not have a risk factor. It is important to consult a doctor if you are experiencing persistent symptoms of colon (or colorectal) cancer. 

Also Read: Does Masturbating Increase Risk of Prostate Cancer or Vice Versa?

How Can You Reduce Your Risk of Colon Cancer?

The risk of colon cancer may be reduced by following these tips: 

• Include physical activity in your daily routine 
• Avoid smoking and alcohol consumption 
• Consume a diet rich in vegetables, fruits, and whole grains, and reduce processed and red meat consumption 
• Get screened for colon cancer, especially if you have a family history of colon cancer or an earlier occurrence of polyps 
• Maintain a healthy body weight⁸ 

Note: Although these tips may help reduce the risk of colon cancer, they cannot guarantee that you will not develop the disease. While some risk factors can be addressed, others, such as family history, cannot be changed. 

Symptoms That Should Not Be Ignored

Colon or related cancers can bring about many symptoms, which include common symptoms like: 

• Dark or red-coloured stool 
• Persistent changes in bowel habits such as diarrhoea, constipation, narrow stools, or a feeling of incomplete bowel emptying³ 
• Persistent abdominal pain, cramps, bloating, or discomfort 
• Unexplained weight loss 
• Anaemia (reduced blood iron levels)⁹ 
• Fatigue/tiredness³

When Should You See a Doctor?

See a doctor if you experience symptoms like blood in your stool, lasting changes in bowel habits, ongoing stomach discomfort, unexplained weight loss, or unusual tiredness⁹. Do not ignore repeated bleeding by assuming it is only due to haemorrhoids. Seek urgent care if you have heavy bleeding, severe abdominal pain, repeated vomiting, or difficulty passing stool or gas^9,10. If you have a family history of colorectal cancer, previous high-risk polyps, IBD, or an inherited condition linked to colorectal cancer, speak with your doctor about the right screening schedule for you^4,7.

Also Read: Is Bowel Leakage a Sign of Cancer?

Conclusion

Anal sex itself is not known to cause colon cancer. Although HPV can be linked to anal cancer, this does not mean that anal sex or HPV causes cancer in the colon. Factors such as age, family history, lifestyle, and certain health conditions can affect the risk of colon cancer. Knowing the warning signs and following recommended screening can help with early detection and timely treatment. 

Frequently Asked Questions (FAQs)

References

1. Diaz JA, Goldman R, Arellano N, Borkan J, Eaton CB. Brief report: Exploration of colorectal cancer risk perceptions among Latinos. J Immigr Minor Health. 2011;13(1):188-192. doi:10.1007/s10903-009-9312-1 https://pubmed.ncbi.nlm.nih.gov/20063065/

2. Anal cancer causes and risk factors. NCI. 2025. Available from: https://www.cancer.gov/types/anal/causes-risk-factors 

3. Colorectal cancer. MedlinePlus. 2024. Available from: https://medlineplus.gov/colorectalcancer.html 

4. Colorectal cancer risk factors. CDC. 2026. Available from: https://www.cdc.gov/colorectal-cancer/risk-factors/index.html 

5. HPV and cancer. NCI. 2025. Accessed August 28, 2026. https://www.cancer.gov/about-cancer/causes-prevention/risk/infectious-agents/hpv-and-cancer 

6. Hsu CH, Lin YJ, Chen YC, et al. Human Papillomavirus and Risk of Colorectal Cancer: An Analysis of Nationwide Claims Data. Medicina (Kaunas). 2022;58(10):1461. doi:10.3390/medicina58101461 https://pubmed.ncbi.nlm.nih.gov/36295621/

7. Colorectal cancer risk factors. American Cancer Society. 2025. Available from: https://www.cancer.org/cancer/types/colon-rectal-cancer/causes-risks-prevention/risk-factors.html 

8. Can colorectal cancer be prevented? American Cancer Society. 2025. Available from: https://www.cancer.org/cancer/types/colon-rectal-cancer/causes-risks-prevention/prevention.html 

9. Symptoms of colorectal cancer. CDC. 2026. Available from: https://www.cdc.gov/colorectal-cancer/symptoms/index.html 

10. Songtanin B, Chu VM, Deb A, Islam S, Islam E, Nugent K. Vomiting and profound weight loss as a clue to the diagnosis of malignant coloduodenal fistula. Proc (Bayl Univ Med Cent). 2022;35(2):237-238. doi:10.1080/08998280.2021.2008220. https://pubmed.ncbi.nlm.nih.gov/35261464/

11. Chen AB, Kalichman L. Pelvic floor disorders due to anal sexual activity in men and women: A narrative review. Arch Sex Behav. 2024;53(10):4089-4098. doi:10.1007/s10508-024-02995-2 https://pubmed.ncbi.nlm.nih.gov/39287780/

12. Anal cancer. MedlinePlus. 2025. Available from: https://medlineplus.gov/analcancer.html 

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