Skip to main content
bowel incontinence

What are the early warning signs of bowel cancer?

It’s easy to dismiss a change in your toilet habits or to brush off stomach aches and bloating as dietary issues. However, if these problems are persistent and unexplained, they may be signs of bowel cancer - and spotting them early is very important.

Bowel cancer, also called colorectal cancer, affects the large bowel, which is made up of the colon and rectum. Around 43,000 people are diagnosed with bowel cancer every year in the UK1.

Although more than nine out of 10 new cases (94%) are diagnosed in people over the age of 50, bowel cancer can affect anyone of any age. More than 16,800 people die from bowel cancer in the UK every year, but it can be treatable and possibly curable - especially if it's diagnosed early.

Genevieve Edwards, chief executive at Bowel Cancer UK, says: "Bowel cancer is the UK’s fourth most common cancer but it doesn’t have to be this way. It’s treatable if diagnosed early and by going straight to your GP it’s possible to rule out bowel cancer first and fast."

Continue reading below

Signs of bowel cancer

Changes in your poo

Symptoms of bowel cancer may include changes in your poo. Your poo may be softer or you may have diarrhoea or constipation that is not usual for you. You may need to poo more or less often than usual, or have blood in your poo - which may look red or black. Additionally, you might often feel like you need to poo, even if you've just been to the toilet.

"Key symptoms to look out for include bleeding from your bottom, blood in your poo, a persistent and unexplained change in bowel habits, unexplained weight loss, extreme tiredness for no obvious reason and a pain or lump in your tummy," says Edwards.

"Most people with these don’t have bowel cancer, but if you experience one or more of them, you should visit your doctor straight away. They may ask you to do a test at home to help decide whether your symptoms need further investigation."

Stomach pain and bloating

Stomach aches and bloating are common problems and can be linked to a number of health issues, from your diet to stress. However, if these problems continue for weeks, they may be an early sign of bowel cancer and you should see your doctor.

Losing weight without trying

Losing weight, losing your appetite or feeling weak - without any obvious explanation as to why - can be possible signs of bowel cancer, along with many other unrelated conditions. You may also feel very tired for no reason.

If you have any of these symptoms for three weeks or more, you should speak to your doctor. Although it may seem embarrassing to talk about your toilet habits, your GP will have heard it all before and will be used to talking about these symptoms.

Bowel cancer in under-50s

Although bowel cancer is more common in people over 50, it's important that everyone is aware of the symptoms. Recently, researchers at the Washington University School of Medicine in St Louis studied more than 5,000 patients under the age of 50 with bowel cancer. Their symptoms before diagnosis included abdominal pain, bleeding from the bottom, diarrhoea and iron deficiency anaemia2.

Yin Cao, a senior investigator for the study, says: "Colorectal cancer is not simply a disease affecting older people. We want younger adults to be aware of and act on these potentially very telling signs and symptoms - particularly because people under 50 are considered to be at low risk, and they don’t receive routine colorectal cancer screening."

What to expect when you speak to your doctor

When you see your doctor, they will ask you about your symptoms, your health in general and your medical history. They may also ask if anyone in your family has had bowel cancer. Your doctor may feel your stomach or ask to do a rectal examination, which is where they put a gloved finger inside your bottom to check for lumps.

It's important not to feel ashamed or embarrassed - and you can ask for a male or female doctor or nurse if you feel uncomfortable. You may also be asked for a poo sample - called a stool sample - for testing.

Your doctor may refer you for more tests or to see a specialist in hospital if they think you have symptoms that need to be investigated, but this doesn’t mean you have cancer.

If you're ever concerned about your health or any changes to your body or toilet habits, it’s always best to speak to your doctor.

Continue reading below

Further reading

  1. Bowel Cancer UK: Bowel Cancer.

  2. Washington University School of Medicine in St Louis: Red flags indicate risk for early-onset colorectal cancer.

Article History

The information on this page is written and peer reviewed by qualified clinicians.

symptom checker

Feeling unwell?

Assess your symptoms online for free