Bowel cancer - Diagnosis

In this section

When to see your GP
When you should see a specialist
Tests for bowel cancer

It's best to see your GP if you have any bowel problems which are worrying you. Your problems may not be cancer but it's important for your GP to find out the cause.

When to see your GP

If you have any of the symptoms described here you should visit your doctor. Don't wait to see if the symptoms go away.[1] Symptoms that might happen if you have colon or rectal cancer are:

A change in your bowel habits that lasts for six weeks (looser or more frequent bowel movements, diarrhoea or constipation, for example)
Blood (bright red or dark spots) in your stools
A feeling that your bowel hasn't emptied properly
Painful cramps, bloating and wind in your lower stomach
Feeling tired and looking pale
Feeling sick
Narrower stools than usual
Loss of appetite.

Some of these symptoms may be due to things that aren't bowel cancer. For example, if you notice blood on the toilet paper when you have a bowel movement, it's much more likely to be caused by piles (haemorrhoids) than cancer. This doesn't mean you should ignore it. You should still tell your GP about these symptoms. Your GP will ask questions about your symptoms to try to find out what is causing them.

If you do have bowel cancer, the sooner you get treatment, the better your chances of surviving.

Questions your GP might ask:

Have you noticed any blood in your stools, in the toilet or on the toilet paper when you have a bowel movement?
Has this ever happened before?
Do you have or try to have more bowel movements than you used to?
Are your bowel movements looser than they used to be?
Do they hurt at all?
How long has this been going on?
Do you ever feel sick or get indigestion?
How's your appetite? Are you eating as much as usual?
What sorts of things do you eat?
How much fruit and vegetables do you eat?
Do you get more tired than you used to?
Do you have any other aches and pains?

Your GP will also examine you. This will probably include:

Feeling for swelling around your stomach or in your abdomen, particularly on the right side
Putting a gloved finger in your back passage (rectum) to feel for any lumps that could be cancerous.

Your GP might also want to do the following tests.

A blood test to check for anaemia. If you are bleeding inside from a tumour or for another reason, you can become anaemic. This is when you feel tired and look pale. It happens because you don't have enough red blood cells in your body.
A stool test (called a faecal occult blood test) to look for signs of blood in your faeces. Sometimes you can't see blood just by looking at your stools, so you need to provide a bit of a stool to be looked at in a laboratory. To learn more about this test, see our information on Bowel cancer screening.

When you should see a specialist

If your GP thinks that you could have cancer, he or she should refer you urgently to a hospital consultant or specialist clinic. You should get an appointment within two weeks of going to the GP.[2]

You are most likely to be referred if any of the following are true.[2]

You have a swelling in the right side of your abdomen that your GP can feel.
You have a lump in your rectum that your GP can feel.
You're 60 or over and you have had bleeding from your rectum and a change in your bowel habits that have lasted for six weeks or more.
You're 60 or over and you have had bleeding from your rectum for six weeks or more. But you don't have piles or a tear around the opening to your back passage (anus) that could be bleeding.
You're 60 or over and you've had a change in bowel habits (looser or more frequent stools) for more than six weeks.
You're a man and have anaemia for no obvious reason.
You're a woman and have anaemia and you don't have periods.

If your GP doesn't think it could be cancer, you may still be referred to a specialist, but the appointment won't be so urgent, and it will probably take longer to see someone. Remember that most people who are referred to see a bowel specialist, including many of those who have an urgent referral, are found not to have cancer.

Seeing a specialist

Like your GP, the specialist will ask you about your symptoms and examine you. This examination will probably include:

Feeling for swelling around your stomach or in your abdomen, particularly on the right side
Putting a gloved finger in your back passage to feel for any lumps that could be cancer.

The specialist will also arrange some tests to look inside your bowel. You should have a special test called an endoscopy.[3] This is the most accurate way of diagnosing early cancers. It works better than another test called a barium enema, which uses X-rays.

The endoscopy involves putting a flexible tube with a light and a viewing lens or camera into your anus to see inside your bowel. You can have an endoscopy called a flexible sigmoidos copy which examines just the last third of your large bowel. Or you can have an endoscopy called a colonoscopy which examines your entire large bowel. You might also have an endoscopy called a proctoscopy which examines your rectum closely.

You'll be given information about eating, drinking and taking medicines before these tests. The day before you have one of these tests, you'll need to take laxatives. These are medicines to empty your bowel.

You shouldn't eat or drink anything on the morning before your test. Just before your test, you might have a bowel wash-out (enema) to help you get rid of any stools that are still there.

All of this will help the specialist to get clearer pictures inside your colon and rectum.

Tests for bowel cancer

Some of these tests are uncomfortable and you may feel embarrassed about what happens. For example, you may get a lot of wind or be unable to control what comes out of your back passage during your tests. You can take medicines to help you relax. Remember that the doctors and nurses who look after you understand the problems you are having.

What tests you have will depend on where the specialist thinks you might have cancer, and which tests are most commonly used in your part of the UK.

The National Institute for Health and Clinical Excellence (NICE) recommends that you have an endoscopy to diagnose bowel cancer.[4] This could be a colonoscopy (which looks at your whole bowel) or a sigmoidoscopy (which looks at only part of it). You should be cared for by a team skilled at treating bowel cancer. (NICE is the organisation that recommends which treatments should be used in the NHS.)

A barium enema

This is when doctors take X-rays of your bowel. A thick, white liquid that contains a chemical called barium will be passed up a tube into your back passage. The barium sticks to the lining of your bowel, and helps things to show up more clearly on the X-ray. A series of X-ray pictures will be taken as the barium liquid passes back down your bowel. Your doctor will check these carefully for any signs of abnormal growths in your bowel.

Your stools may be white for a few days after a barium enema, while the white liquid gets out of your body. This is nothing to worry about.

A barium enema was often used in the past to diagnose bowel cancer. But a different test called an endoscopy is now a more accurate method. You should have either a colonoscopy or a sigmoidoscopy to find out if you have this cancer.[4]

Proctoscopy

This is a kind of endoscopy. The doctor puts a small viewing tube called a proctoscope into your back passage to look inside your rectum. A light inside the proctoscope shines inside your back passage so that your doctor can check for abnormal growths. It can be uncomfortable to have this test, but it shouldn't hurt.

Sigmoidoscopy

This allows your doctor to look further into your bowel. This is a kind of endoscopy.

Your doctor will use a viewing tube called a sigmoidoscope, which is put into your rectum and the lower part of your colon. The doctor may use a flexible sigmoidoscope which allows him or her to look around bends in your colon and to go further up. It's also more comfortable for you.

Like the proctoscope, the sigmoidoscope has a light which shines inside your bowel. There's a camera on the end of the sigmoidoscope, so the doctor can look at the inside of your bowel on a big screen in the operating theatre.

Colonoscopy

This test helps your specialist see inside your whole colon and rectum. This is a kind of endoscopy.

Like the flexible sigmoidoscope, the colonoscope is a flexible tube that is put into your rectum and colon through your anus. Before you have a colonoscopy, you can have a painkiller or medicine to make you sleepy and relaxed. This will make the test more comfortable for you. In fact, you may not remember any of it when you are fully awake again.

We've prepared some extra information for people thinking of having this test. To read more, see Colonoscopy.

Biopsy

During a proctoscopy, sigmoidoscopy or colonoscopy, your doctor can take a small sample of any growths or other abnormal tissue that he or she finds in your colon or rectum. This is called a biopsy. The tissue can be examined in the laboratory to see if it is cancer.

Small, fleshy lumps in the bowel are called polyps. They are not cancer but they can become cancer. So doctors usually remove them if they see them. To find out more about checking for polyps, see Bowel cancer screening.

Further tests

If your doctor finds that you do have cancer in your colon or rectum, you will probably be offered some more tests to see if it has spread. The results will help your doctor stage your cancer and recommend what treatment will help you most. (To read about the stages of bowel cancer, see What stage is your cancer?)

To help stage your cancer, you may be offered these tests.

An ultrasound scan: This uses sound waves to look inside your abdomen to see if your cancer has spread to your liver or another part of your abdomen.
A CT scan: This uses computerised X-rays to build a three-dimensional picture of the organs and tissues inside your abdomen. It can show how big the tumour is and whether it has spread outside your bowel.
An MRI scan: This uses a magnetic field to get very detailed pictures of the inside your body and show whether the cancer has spread.

Screening

When people first get bowel cancer, they might not have any symptoms, so they don't go to the doctor. This means that often doctors diagnose this cancer only when it is more advanced and the person is having symptoms. But older people, who are more at risk of bowel cancer, can have screening tests to spot any cancer earlier.

To learn more, see Bowel cancer screening.

References

Scottish Intercollegiate Guidelines Network. Management of colorectal cancer. Scottish Intercollegiate Guidelines Network guideline No. 67. 2003. Available at: http://www.sign.ac.uk/guidelines/published/numlist.html (accessed on 2 July 2007).
Department of Health. Referral guidelines for suspected cancer 2000. Available at http://www.dh.gov.uk/assetRoot/04/01/44/21/04014421.pdf (accessed on 10 May 2006).
Hobbs FD. ABC of colorectal cancer; the role of primary care. BMJ. 2000; 321: 1068-1070.
National Institute for Health and Clinical Excellence. Healthcare services for bowel (colorectal) cancer: Understanding NICE guidance: information for the public. Available at http://www.nice.org.uk. Accessed on 27 July 2005.

Glossary

liver: Your liver is a large organ that sits on the right side of your body, just below your rib cage. It does several important things, including processing and storing nutrients from food, and breaking down chemicals, such as alcohol.
haemorrhoids: Haemorrhoids are swollen veins in the anus. Sometimes you can see or feel them and sometimes they are inside the anus. Haemorrhoids can hurt and bleed. They usually happen when you strain a lot to pass a stool.
anaemia: Anaemia is caused by having too few red blood cells. People with anaemia look pale and get tired easily, among other things.
diarrhoea: Diarrhoea is when you have loose, watery stools and you need to go to the toilet far more often than usual. Doctors say you have diarrhoea if you need to go to the toilet more than three times a day.
constipated: When you're constipated, you have difficulty passing stools (faeces). Your bowel movements may be dry and hard. You may have fewer bowel movements than usual, and it may be a strain when you try to go.
red blood cells: Red blood cells are the part of your blood that makes it red. Their main job is to carry oxygen from your heart and lungs to the tissues of your body. Once these cells unload oxygen, they pick up carbon dioxide. They take carbon dioxide back to your lungs so it can be breathed out of your body.
X-ray: X-rays are pictures taken of the inside of your body. They are made by passing small amounts of radiation through your body and then onto film.
laxative: A laxative is a kind of medicine you can buy over the counter. Laxatives empty your bowels by making you go to the toilet often.
ultrasound: Ultrasound is a tool doctors use to create images of the inside of your body. An ultrasound machine sends out high-frequency sound waves, which are directed at an area of your body. The waves reflect off parts of your body to create a picture. Ultrasound is often used to see a developing baby inside a woman's womb.
CT scan: A CT scan is a type of X-ray. It takes several detailed pictures of the inside of your body from different angles. CT stands for computed tomography. It is also called a CAT scan (computed axial tomography).
MRI scan: A magnetic resonance imaging (MRI) machine uses a magnetic field to create detailed pictures of the inside of the body.

This information does not replace medical advice. If you are concerned you might have a medical problem please ask your Boots pharmacy team in your local Boots store, or see your doctor.

Bowel cancer - Diagnosis

In this section

When to see your GP