Bowel cancer symptoms: what to look for and when to see a GP

Bowel cancer is cancer found anywhere in the large bowel, which includes the colon and rectum. The NHS lists the following possible symptoms. Cancer Research UK says cancer in the colon and cancer in the rectum have similar symptoms.

• 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, or 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 the NHS says are signs of anaemia that can be caused by bowel cancer.

Cancer Research UK says blood in your poo can be a sign of bowel cancer, but it is often due to other causes. Most often it comes from piles (haemorrhoids), especially if it is bright red, fresh blood. Blood from higher up in the bowel does not look bright red; it goes dark red or black and can make your poo look like tar. That type of bleeding can be a sign of cancer higher up the bowel, or it could be from something else such as a bleeding stomach ulcer.

Bowel Cancer UK says bright red blood may come from haemorrhoids or from non-cancerous growths (polyps), but it may also be caused by bowel cancer, and dark red or black blood may come from the bowel or stomach. Its advice is to tell your GP about any bleeding so they can find out what is causing it. Cancer Research UK adds that your doctor will not think you are wasting their time.

The NHS says to see a GP if you have any symptoms of bowel cancer, because if it is bowel cancer, finding it early can make it easier to treat. It says to try not to be embarrassed.

Bowel Cancer UK says not everyone will have all the symptoms, or they may get different symptoms at different times, and that even one symptom is worth reporting. Knowing what is normal for you matters, because there is no rule for how often you should be going to the toilet. It suggests keeping a note of your symptoms to help explain them at your appointment.

Cancer Research UK says many of the conditions that can cause these symptoms are much less serious than cancer, such as piles, infections or inflammatory bowel disease.

The NHS gives two levels of urgent advice.

Ask for an urgent GP appointment or get help from NHS 111 if your poo is black or dark red, or you have bloody diarrhoea.

Call 999 or go to A&E if you are bleeding non-stop from your bottom, or there is a lot of blood or you see large blood clots when you poo. The NHS says not to drive to A&E; ask someone to drive you or call 999, and bring any medicines you take.

Cancer Research UK also says sometimes cancer can block the bowel (a bowel obstruction), with cramping tummy pains, bloating, constipation with being unable to pass wind, and being sick. It says a bowel obstruction is an emergency and you should see a doctor quickly or go to A&E.

The NHS says the doctor will ask about your symptoms, general health, medical history and whether anyone in your family has had bowel cancer. Depending on your symptoms, the doctor may feel your tummy and ask to do a rectal examination, putting a gloved finger inside your bottom to check for lumps. You can ask for a male or female doctor or nurse and for someone else to be in the room.

You may be asked for a stool sample or be given a home test kit called a faecal immunochemical test (FIT) to send to a lab. These check whether you are bleeding from your bowel, which can be a sign of bowel cancer. You may also be asked to have a blood test. Bowel Cancer UK says the FIT result tells your GP whether you need further tests.

If the GP thinks you have symptoms that could be cancer, the NHS says you may get an urgent referral for more tests or to see a specialist in hospital. This 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 your bowel. It may be uncomfortable but should not be painful, and you will be offered a sedative and painkillers. During the test a small sample of the lining of your bowel may be taken (a biopsy).

You may get some results on the same day as the colonoscopy or after a few days or weeks. If you are told you have bowel cancer, the NHS says you may need more tests, such as a CT scan, an MRI scan, a PET scan, blood tests and genetic testing, to show how far the cancer has spread. A team of specialists will help you through diagnosis and treatment, including a clinical nurse specialist as your main point of contact.

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 can make you more likely to get it. It says you may be more likely to get bowel cancer if:

• You are over 50.

• You smoke.

• You are overweight.

• A close relative has had bowel cancer.

• You have inflammatory bowel disease, which includes Crohn's disease and ulcerative colitis.

• You have small growths in your bowel called bowel polyps.

• You have Lynch syndrome or familial adenomatous polyposis (FAP).

The NHS says bowel cancer screening uses a FIT test you do at home and post for testing. It is offered to people aged 50 to 74 every 2 years, and people aged 75 or over can ask for the test by calling the screening helpline. It can help find cancer early, before you have any symptoms.

Screening is different from getting symptoms checked. If you have symptoms, the NHS says it is important to see a GP rather than waiting for a screening kit.

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 surgery, chemotherapy, radiotherapy and targeted medicines.

Surgery may remove the cancer, with part or all of the bowel around it, and you may need a colostomy or ileostomy that may be temporary or permanent. Chemotherapy may be given before surgery to shrink the cancer or after surgery to try to stop it coming back. Radiotherapy may be used for cancer in the rectum or cancer that has spread. Targeted medicines or immunotherapy are sometimes used for advanced bowel cancer.

Bowel Cancer UK says the earlier bowel cancer is diagnosed, the more treatable it is likely to be.

On the NHS, assessment usually starts with your GP, who may do an examination, a FIT test and blood tests and refer you urgently for a colonoscopy or specialist review if symptoms could be cancer. You will be supported by a specialist team if cancer is found.

Some people choose to see a private gastroenterologist or colorectal surgeon, or to pay for a colonoscopy, for speed or choice of date. The tests and safety information are the same in either setting. Tell your GP about any private results so your records are complete, and do not delay seeking help for black or bloody poo or non-stop bleeding.