Colorectal Cancer (Bowel Cancer) Symptoms, Screening and Diagnosis


Signs and symptoms of colorectal cancer

Colorectal cancer might not cause symptoms right away, but when they do appear, common symptoms may include:

  • an ongoing change in bowel habits that lasts for more than a few days (diarrhoea, constipation or feeling that the bowel does not empty completely)
  • stools that are narrower than usual
  • blood (either bright red or very dark) in the stool
  • rectal bleeding with bright red blood
  • frequent gas pains, bloating, fullness or abdominal cramps
  • weight loss for no known reason
  • feeling very tired (weakness and fatigue)

Do see your doctor if you have any of these symptoms, especially if you are at a higher risk of developing colorectal cancer.

Seeing your doctor and being diagnosed

When you go to see your doctor, explain your symptoms in full. It may help to write everything down before you go to ensure you tell them everything, including which symptoms you have noticed, when they started, when and how often they happen.

Tell your doctor about any existing illnesses you have (particularly inflammatory bowel disease or similar conditions), and any family history of cancer.

Take a friend or relative along for support if needed. Sometimes it is hard to remember all the questions you wanted to ask or to take in everything the doctor is telling you; having someone there can really help.

Also remember, there is no need to be embarrassed. Doctors are very used to discussing intimate problems and everything you tell them is completely confidential.

Your doctor might do a general examination and will refer you for tests.

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