Bowel cancer
Bowel cancer (colorectal cancer) is the fourth most common cancer in the UK. It develops in the large bowel, which includes the colon and rectum. Most cases occur in people over 50, though rates in younger adults have been rising.
Symptoms may include:
- A persistent change in bowel habit, such as going more often or having looser stools
- Blood in the stool without an obvious cause
- Abdominal pain, bloating or discomfort
- Unexplained weight loss or persistent fatigue
The NHS Bowel Cancer Screening Programme uses a faecal immunochemical test (FIT), also known as qFIT, to detect tiny amounts of blood in the stool that may not be visible. The programme invites adults aged 50 to 74 every two years.
When bowel cancer is caught early, treatment is significantly more effective. Carcinoembryonic antigen (CEA) is a blood marker used primarily to monitor treatment rather than for initial screening. Polygenic risk scores can offer additional insight into inherited susceptibility.
Causes of Bowel cancer
Bowel cancer develops when cells in the lining of the large bowel grow abnormally and form polyps, some of which can become cancerous over time.
Risk factors include:
- Age, with the large majority of cases diagnosed in people over 50
- Diet high in red and processed meat and low in fibre
- Obesity and physical inactivity
- Smoking and regular heavy alcohol consumption
- Family history of bowel cancer, particularly in a first-degree relative diagnosed before 50
- Inherited genetic conditions such as Lynch syndrome (hereditary non-polyposis colorectal cancer) and familial adenomatous polyposis (FAP)
- Inflammatory bowel disease, particularly longstanding ulcerative colitis or Crohn's colitis
- Type 2 diabetes, which is associated with a modest increase in risk
Many cases of bowel cancer are preventable. Maintaining a healthy weight, eating a high-fibre diet, reducing red and processed meat intake, staying physically active, limiting alcohol and not smoking all help reduce risk.
Tests that can help check this condition
Learn more on the official NHS page .
