Cancer can sometimes start in the small bowel (small intestine), but small bowel cancer is much rarer than large bowel cancer.
Bowel cancer is one of the most common types of cancer diagnosed in the UK, with around 40,000 new cases diagnosed every year.
About one in every 20 people in the UK will develop bowel cancer during their lifetime.
Signs and symptoms
The three main symptoms of bowel cancer are blood in the stools (faeces), changes in bowel habit (such as to more frequent, looser stools) and abdominal (tummy) pain. However, these symptoms are very common and most people with them do not have bowel cancer.
For example, blood in the stools is more often caused by haemorrhoids(piles), and a change in bowel habit or abdominal pain is usually due to something you have eaten.
As almost nine out of 10 people with bowel cancer are over 60 years old, these symptoms are more important as people get older. They are also more significant when they persist despite simple treatments.
Most people who are eventually diagnosed with bowel cancer have one of the following symptom combinations:
- a persistent change in bowel habit causing them to go to the toilet more often and pass looser stools, usually together with blood on or in their stools
- a persistent change in bowel habit without blood in their stools, but with abdominal pain
- blood in the stools without other haemorrhoid symptoms such as soreness, discomfort, pain, itching or a lump hanging down outside the back passage
- abdominal pain, discomfort or bloating always provoked by eating, sometimes resulting in a reduction in the amount of food eaten and weight loss
The symptoms of bowel cancer can be subtle and don’t necessarily make you feel ill.
Read more about the symptoms of bowel cancer.
When to seek medical advice
Try the bowel cancer symptom checker for advice on treatments you can try to see if your symptoms get better and when you should see your GP to discuss whether any tests are necessary.
Your doctor will probably carry out a simple examination of your tummy and bottom to make sure you have no lumps, and they may arrange a simple blood test to check for iron deficiency anaemia (as this can indicate whether there is any bleeding from your bowel that you haven’t been aware of).
In some cases, your doctor may decide it is best for you to have a simple test in hospital to make sure there is no serious cause for your symptoms.
Make sure you return to your doctor if your symptoms persist or keep coming back after stopping treatment, regardless of their severity or your age.
Read more about diagnosing bowel cancer.
Who’s at risk?
It’s not known exactly what causes bowel cancer, but there are a number of things that can increase your risk. These include:
- age – almost nine in 10 cases of bowel cancer occur in people aged 60 or over
- diet – a diet high in red or processed meats and low in fibre can increase your risk
- weight – bowel cancer is more common in people who are overweight or obese
- exercise – being inactive increases the risk of getting bowel cancer
- alcohol and smoking – a high alcohol intake and smoking may increase your chances of getting bowel cancer
- family history – having a close relative (mother or father, brother or sister) who developed bowel cancer below 50 years of age puts you at a greater lifetime risk of developing the condition
Some people are also at an increased risk of bowel cancer because they have another condition that affects their bowel, such as severe ulcerative colitis or Crohn’s disease over a long period of time.
Treatment and outlook
Bowel cancer can be treated using a combination of different treatments, depending on where the cancer is in your bowel and how far it has spread.
The main treatments are:
- surgery to remove the cancerous section of bowel, this is the most effective way of curing bowel cancer and is all that many people need
- chemotherapy – where medication is used to kill cancer cells
- radiotherapy – where radiation is used to kill cancer cells
- biological treatments – a newer type of medication that increase the effectiveness of chemotherapy and prevent the cancer from spreading
As with most types of cancer, the chance of a complete cure depends on how far the cancer has advanced by the time it is diagnosed. If the cancer is confined to the bowel then surgery will usually be able to completely remove it.
Overall, between seven and eight in every 10 people with bowel cancer will live at least one year after diagnosis and more than half of those diagnosed will live at least another 10 years.
Every year, around 16,000 people die as a result of bowel cancer.