Colon cancer: 5 key symptoms to know

Written by: Dr Aathavan Loganayagam
Published: | Updated: 21/08/2019
Edited by: Laura Burgess

Colon cancer used to primarily be a concern in people over the age of 50. However, population studies are warning younger age groups of the risks of colon cancer. People under the age of 50 are now four times more at risk than people were in 1990.

Lots of people know that bad things happen, but they never suspect it could happen to them. This is a huge mistake, since underestimating or ignoring your symptoms because you think you're too young to have cancer could be a deadly mistake. Leading London gastroenterologist Dr Loganayagam offers his advice on the five cardinal symptoms that you need to be aware of:

1. Tiredness
This is the most common symptom of colon cancer. Tumours slowly overtake the digestive tract and, eventually, your body won't be able to absorb key nutrients. Anaemia caused by an iron deficiency makes individuals feeling weak or exhausted all the time.

2. Rectal bleeding
There are a lot of minor causes of anal canal bleeding like haemorrhoids (piles) or a small tear. Many people diagnosed with colon cancer believed they suffered from haemorrhoids because the itching and bleeding caused by a tumour were very similar.

Read more: rectal bleeding – what does it mean?

3. Bloody faeces
If your stool is vibrant red, seek medical attention because this indicates active intestinal bleeding. However, if your stool has been dark or tar-like, this may mean you're passing a lot of dried altered blood. Either way, blood in your stool is abnormal and not a good sign. You need to get examined.

4. Change in bowel habit
Colon cancers can affect the shape, frequency, or consistency of the faeces. Diarrhoea, constipation, or feeling like you haven't finished passing your stool after defecation can also occur. If a tumour leads to narrowing inside the lower end of the large bowel, then you'll notice that the stool is extremely thin because of the obstruction. If the bowel movements don't improve after a week, go to your doctor.

5. Abdominal pain
If you're experiencing unexplained cramps, tenderness, nausea, or vomiting, colon cancer may be to blame. See the doctor immediately because these symptoms indicate that your cancer has spread beyond your intestines. Cancer is scary, and no one wants to have it, but don't let your fear stop you from seeking medical attention if you feel like something in your body is wrong. It could save your life.


Read more: testing for colon cancer

If you are experiencing the symptoms above, then do not hesitate to book an appointment with a specialist

By Dr Aathavan Loganayagam

Dr Aathavan Loganayagam trained in medicine at Guy’s, King's and St. Thomas’ medical schools. He then underwent rigorous structured specialty training in gastroenterology and general internal medicine in the well respected South London training programme.

He then spent two years during postgraduate training as a research and endoscopy fellow at Guy’s and St Thomas’ Hospitals, London. His research was in the fields of pharmacogenetics, inflammatory bowel disease and gastrointestinal malignancy. He has received awards and grants for outstanding research work, including the prestigious NHS Innovation London Award.

Dr Loganayagam has numerous publications in peer reviewed journals on all aspects of gastroenterology. He is actively involved in clinical research. He has particular local expertise in the practice of personalised medicine and the utilisation of novel therapeutic agents in the treatment of complex inflammatory bowel disease. He is currently the lead clinician for endoscopy at Queen Elizabeth Hospital, Woolwich.

Diagnostic and advanced therapeutic endoscopy remains a major part of his clinical expertise, including assessment and treatment of inflammatory bowel disease, strictures, polyps and cancers.

Dr Loganayagam is an approachable doctor who takes pride in his communication skills with patients. He is keen to ensure that patients are fully informed and involved in all aspects of their care.

View Profile

Overall assessment of their patients

This website uses its own and third-party cookies to collect information in order to improve our services, to show you advertising related to your preferences, as well as to analyse your browsing habits..