Bowel cancer is a general term for cancer that begins in the large bowel. Depending on where the cancer starts, bowel cancer is sometimes called colon or rectal cancer.
Bowel cancer is one of the most common types of cancer diagnosed in the USA, with around 40,000 new cases diagnosed every year.
About 1 in every 20 people in the USA will develop bowel cancer in their lifetime.
Signs and symptoms
The three main symptoms of bowel cancer are blood in the stools (faeces), changes in bowel habit – such as 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 the result of something you have eaten.
As almost 9 out of 10 people with bowel cancer are over the age of 60, 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 combination of symptoms:
- a persistent change in bowel habit that causes 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.
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.
They may also arrange for a simple blood test to check for iron deficiency anaemia – 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.
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 9 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 under the age of 50 puts you at a greater lifetime risk of developing the condition
Some people have an increased risk of bowel cancer because they have another condition that affects their bowel, such as severeulcerative colitis or Crohn’s disease, over a long period of time.
Read more about the causes of bowel cancer and preventing bowel cancer.
Bowel cancer screening
To detect cases of bowel cancer sooner, the NHS offers two types of bowel cancer screening to adults registered with a GP in England:
- faecal occult blood (FOB) test – all men and women aged 60 to 74 are invited to carry out an FOB test at home. They’re sent the home test kit every two years through the post until they reach the age of 74. The FOB test checks for the presence of blood in a stool sample, which could be an early sign of bowel cancer.
- bowel scope screening – this additional one-off test is being gradually introduced in England. It is offered to men and women at the age of 55. As of March 2015, about two-thirds of screening centres were beginning to offer this test to 55-year-olds. It involves a doctor or nurse using a thin, flexible instrument to look inside the lower part of the bowel and remove any small growths called polyps, which could eventually turn into cancer.
Screening plays an important part in the fight against bowel cancer as it can help detect bowel cancer before it causes obvious symptoms, which increases the chances of people surviving the condition.
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 – the cancerous section of bowel is removed; it 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 increases the effectiveness of chemotherapy and prevents the cancer spreading
As with most types of cancer, the chances of a complete cure depends on how far it has advanced by the time it is diagnosed. If the cancer is confined to the bowel, surgery will usually be able to completely remove it.