Bowel cancer: symptoms, causes, tests and treatment

The NHS lists the main symptoms of bowel cancer. Some of these are very common and can be caused by other conditions, so having them does not definitely mean you have bowel cancer, but it is important to get checked by a GP.

• Changes in your poo, such as softer poo, diarrhoea or constipation that is not usual for you.

• Needing to poo more or less often than is usual for you.

• Blood in your poo, which may look red or black.

• Bleeding from your bottom.

• Often feeling like you need to poo, even if you have just been to the toilet.

• Tummy pain.

• A lump in your tummy.

• Bloating.

• Losing weight without trying.

• Feeling very tired or short of breath, which are signs of anaemia that can be caused by bowel cancer.

The NHS says that if you have symptoms of bowel cancer it is important to get checked. See a GP if you have any symptoms of bowel cancer, and try not to be embarrassed because the doctor or nurse will be used to talking about these symptoms.

At the GP appointment, the NHS says the doctor will ask about your symptoms, general health, medical history and family history of bowel cancer. They may feel your tummy and do a rectal examination, where a gloved finger is put inside your bottom to check for lumps. You can ask for a male or female doctor or nurse and for someone else to be present. You may be asked for a poo sample or given a FIT home test kit to check for bleeding from the bowel, and you may have a blood test.

The GP may make an urgent referral for more tests or to see a specialist, which does not definitely mean you have cancer. The NHS says the main test for bowel cancer is a colonoscopy, where a thin flexible tube with a camera is used to look inside the bowel. It may be uncomfortable but should not be painful, and you are offered a sedative and painkillers. A small sample of the bowel lining may be taken (a biopsy). You may get some results on the same day or after a few days or weeks.

If bowel cancer is found, you may need more tests, which can include a CT scan, an MRI scan, a PET scan, blood tests and genetic testing, to show how far it has spread and whether certain gene changes are involved. A clinical nurse specialist will be your main point of contact.

The NHS says bowel cancer screening is a test you do at home that checks for signs of bowel cancer. It uses a faecal immunochemical test (FIT) to look for blood in a sample of poo, which could be a sign of bowel cancer. It is currently offered to people aged 50 to 74 every 2 years, because the risk gets higher as you get older. People aged 75 or over can ask for the test.

You will usually get results within 2 weeks of sending the sample. If no further tests are needed, you will be offered screening again in 2 years. If blood is found, you will be invited to see a specialist nurse and will usually need a colonoscopy. The NHS says blood in your poo does not always mean cancer, as there are more common and less serious causes such as an anal fissure or bowel polyps. It also says a screening result of no further tests does not always mean you do not have bowel cancer, so it is important to know the symptoms and see a GP if you have symptoms.

The NHS says treatment depends on the size of the cancer, whether it is in the colon or rectum or both, whether it has spread, whether it has certain genetic changes, and your age and general health. You may be offered a combination of treatments. Your specialist treatment team will explain the benefits and side effects and work with you on the plan.

The NHS says bowel cancer is cancer found anywhere in the large bowel, which includes the colon and rectum. The large bowel is part of the digestive system, helps absorb water from food and removes food waste. How serious it is depends on how big the cancer is, if it has spread and your general health. Bowel cancer is one of the most common types of cancer in the UK, and screening can pick it up early, which may mean it is easier to treat.

The NHS says it is not always known what causes bowel cancer, but it can be caused by genetic changes, lifestyle and environmental factors, and certain health conditions make it more likely.

• Being over 50.

• Smoking.

• Being overweight.

• A close relative who has had bowel cancer.

• Inflammatory bowel disease, which includes Crohn's disease and ulcerative colitis.

• Small growths in the bowel called bowel polyps.

• Lynch syndrome or familial adenomatous polyposis (FAP).

The NHS says you cannot always prevent bowel cancer, but there are things you can do to lower your chance of getting it. It is also important to get any symptoms checked by a GP.

• Eat a healthy diet including at least 5 portions of fruit and vegetables a day.

• Stay active and exercise regularly.

• Lose weight if you are overweight.

• Quit smoking.

• Drink less alcohol.

• Eat less red and processed meat.

Bowel symptoms are common and have many causes. The NHS says some symptoms of bowel cancer can be caused by other conditions, and that blood in the poo can have more common, less serious causes. Examples named in the NHS pages used for this guide include anal fissure and bowel polyps. A GP can assess whether tests such as a FIT, blood tests or a colonoscopy are needed.

On the NHS the first step is the GP, who may use a FIT kit and blood tests and make an urgent referral for a colonoscopy if cancer could be the cause. If cancer is diagnosed you are supported by a specialist team including a clinical nurse specialist.

Some people choose a private consultation or colonoscopy, usually for speed. In general terms the tests are the same. It is worth asking how a diagnosis would be fed into an NHS cancer team, who would coordinate treatment, and how results are shared with your GP.