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Symptoms

Find out about possible symptoms of bowel cancer and when to see your doctor.

Possible symptoms of bowel cancer

The symptoms of bowel (colorectal) cancer can include:

  • bleeding from the back passage (rectum) or blood in your poo
  • a change in your normal bowel habit
  • a lump that your doctor can feel in your back passage or tummy (abdomen), more commonly on the right side
  • a feeling of needing to strain in your back passage (as if you need to poo), even after opening your bowels
  • losing weight
  • pain in your abdomen or back passage
  • tiredness and breathlessness caused by a lower than normal level of red blood cells (anaemia)

Bowel obstruction

Sometimes cancer can block the bowel. This is called a bowel obstruction. The symptoms include:

  • griping pains in the abdomen
  • feeling bloated
  • constipation and being unable to pass wind
  • being sick

All the symptoms mentioned above can be caused by other conditions. Many of these are much less serious than cancer, such as piles (haemorrhoids), infections or inflammatory bowel disease. If you are young and have bleeding from the back passage with itching and soreness, you are much more likely to have piles than bowel cancer.

Blood in poo

Blood in poo (stools or faeces) can be a sign of bowel cancer. But more often it is due to other causes. See your GP if you are worried about any symptoms that you think could be caused by cancer in the bowel.

Most often, blood in the stool is from piles (haemorrhoids), especially if it is bright red, fresh blood. Piles are like swollen veins in the back passage. These veins are fragile and can easily get damaged when you pass a bowel motion, causing a little bleeding.

Blood from higher up in the bowel doesn't look bright red. It goes dark red or black and can make your bowel motions look like tar. This type of bleeding can be a sign of cancer higher up the bowel. Or it could be from a bleeding stomach ulcer for example.

It is important to go to your doctor if you have any bleeding and get checked.

Your doctor won't think you are wasting their time with this sort of symptom. You will almost certainly have a rectal examination. This means the doctor puts a gloved finger into your back passage and feels for anything abnormal. 

You will need to go to the hospital for bowel cancer tests if your doctor can't feel anything abnormal, or feels a lump that might be cancer.

Last reviewed: 
15 Aug 2015
  • Suspected cancer: recognition and referral
    The National Institute for Health and Care Excellence (NICE), June 2015

  • Cancer: Principles and Practice of Oncology (10th edition)
    VT De Vita, TS Lawrence and SA Rosenberg
    Lippincott, Williams and Wilkins, 2015 

  • Cancer and its management (7th edition)
    J Tobias and D Hochhauser
    Blackwell, 2015

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