Also known as colorectal cancer, bowel cancer is a type of cancer that begins in the large bowel (colon) or the back passage (rectum). Although the exact cause of bowel cancer is currently unknown, there are some factors that may make it more likely for you to develop it, these include:

  • Genetic conditionsGenetic conditions
  • Digestive disorders
  • Obesity
  • Excessive use of alcohol
  • Smoking
  • Family history
  • Age

See also: What is the Function of the Bowel?

Common factors associated with bowel cancer

It’s important to note that having a risk factor doesn’t mean you will contract a certain disease; some people may not have any known risk factors and still get the disease. Some of the most common factors that are associated with bowel cancer tend to include:

See also: What Affects Bowel Function?

Genetic conditions

According to the NHS [1], there are two inherited conditions that may lead to bowel cancer:

  • Familial adenomatous polyposis (FAP) FAP can trigger the development of non-cancerous growths inside the bowel or colon from a young age

  • Hereditary non-polyposis colorectal cancer (HNPCC) Also referred to as lynch syndrome, HNPCC is a genetic mutation which can increase risk of developing bowel cancer

Digestive disorders

Bowel cancer is more common in those with inflammatory bowel diseases such as Crohn’s disease or ulcerative colitis for more than 10 years.


More than 1 in 20 cancers are caused by excess weight, with bowel cancer being one of them [2]. The good news is small changes to reduce your weight can make a difference to your overall health and may help lower your chances of developing bowel cancer.

Excessive use of alcohol

Alcohol use is linked to an increased risk of bowel cancer, particularly if you drink regularly or drink large amounts. If you drink alcohol, The American Cancer Society recommends drinking no more than 2 drinks a day if you’re male and 1 drink a day if you’re female [3].


Smoking is commonly associated with lung cancer, but it also has a strong link to other cancers - bowel cancer included. If you smoke and would like to hear more about quitting, read our guide to what happens when you quit smoking.

Family history

Having a close family relative who has had bowel cancer can increase your risk of developing the condition. If you’re concerned about your family history and bowel cancer, it’s important to reach out to your family doctor to discuss further.


Your risk of contracting bowel cancer increases as you get older. In fact, according to The Centers for Disease Control and Prevention estimate that about 90% of cases occur in people who are ages 50 years or older [4].

LetsGetChecked’s at-home Bowel Cancer Screening Test can help identify the presence of cancerous or precancerous growths in the bowel by detecting blood that is invisible to the naked eye.

You should consider getting screened if:

  • You are experiencing gastrointestinal symptoms
  • You have a history of adenomas (benign tumors)
  • You have inflammatory bowel disease* (which includes Crohn's disease and ulcerative colitis)
  • You have an inherited syndrome (e.g. Lynch syndrome/HNPCC or FAP)
  • You have type 2 diabetes
  • You have undergone radiation therapy

See also: How Can You Screen For Bowel Cancer From Home?


  1. NHS. Bowel cancer. Online:, 2019
  2. Cancer Research UK. Does obesity cause cancer? Online:, 2018
  3. American Cancer Society. Colorectal Cancer Risk Factors. Online:, 2020
  4. Centers for Disease Control and Prevention. What Are the Risk Factors for Colorectal Cancer? Online:, 2020