The three main symptoms of bowel cancer are blood in the stools (faeces), a change in bowel habit (such as to more frequent, looser stools) and abdominal (tummy) pain.

However, these symptoms are very common. Blood in the stools is usually caused by haemorrhoids (piles) and a change in bowel habit or abdominal pain is often due to something you have eaten.

In the UK, an estimated 7 million people have blood in the stools each year and even more people have temporary changes in bowel habit and abdominal pain.

Most people with these symptoms do not have bowel cancer.

As the vast majority of people with bowel cancer are over 60 years old, these symptoms are more important as people get older. They are also more significant when they persist in spite of simple treatments.

Most patients with bowel cancer present with one of the following symptom combinations:

• a persistent change in bowel habit, causing 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 what 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 you will probably perform a simple examination of your tummy and bottom to make sure you have no lumps and a simple blood test to check for iron deficiency anaemia (as this can indicate whether there is any bleeding from your bowel you haven’t been aware of).

In some cases, your doctor may decide it is best 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.

Read more about diagnosing bowel cancer.

Bowel obstruction

In some cases, bowel cancer can stop digestive waste passing through the bowel. This is known as a bowel obstruction.

Symptoms of a bowel obstruction can include:

• severe abdominal pain, which may initially come and go
• not being able to pass stools when you go to the toilet
• noticeable swelling or bloating of the tummy
• vomiting

A bowel obstruction is a medical emergency. If you suspect your bowel is obstructed, you should see your GP quickly and if this isn’t possible go to the accident and emergency (A&E) department of your nearest hospital.

Want to know more?

• Association of Coloproctology of Great Britain and Ireland: bowel cancer symptom checker
• Cancer Research UK: bowel cancer symptoms
• Macmillan: symptoms of colon and rectal cancer
• Beating Bowel Cancer: symptoms
• Bowel Cancer UK: symptoms of bowel cancer
• Bowel Cancer Information: key symptoms