What are bowel cancer signs and symptoms?

A sign is a presentation that can be seen or felt by someone else. In some cases, bowel cancer may present a mass or lump in the abdomen or in the rectum that can be detected during a doctor’s exam.

A symptom is a feeling or something unusual you notice, such as fatigue, weakness or cramping.

bowel pain

How does bowel cancer produce signs and symptoms?

When the cells of a polyp are abnormal and reproduce rapidly, the polyp grows large and the cells begin to form a cancerous mass or tumour. Many of the symptoms of bowel cancer may not occur until the tumour has grown and the cancer has advanced. Then, the symptoms produced by the tumour will largely depend on the where it is located in the large intestine.

Bowel cancer and the tumours can hinder the large intestine’s ability to absorb nutrients and to rid the body of waste products, causing changes in bowel movements and unexplained weight loss. Also, tumours that bleed can lead to a shortage of red blood cells, causing anaemia which leads to fatigue and weakness.

Staging describes the size and severity of the cancer and helps to inform the diagnostic and treatment approach. In Stage 0, cancerous cells are found in the innermost layer of the bowel wall. In Stage 1, cancerous cells may have spread to the muscle layer of the colon wall. Stages 2A-C indicate a localised spread, while Stages 3A-C and 4 are advanced or secondary bowel cancer stages and indicate either a local or distant spread.

intestinal tumour

What are the common general signs and symptoms of bowel cancer?

It’s important to note that many bowel cancer signs and symptoms are also associated with other diseases and conditions and may not necessarily indicate bowel cancer.

Early bowel cancer may not produce any signs or symptoms. As it advances and the tumour grows or multiplies, it may produce one or more of the following symptoms.

  • Rectal bleeding or blood in the stool
  • Change in bowel habits, either having more bowel, smaller movements; more constipation (Any noticeable change from what is normal and regular)
  • A change in stool appearance or consistency such mucus in the stools or narrower stools
  • Diarrhoea or constipation that lasts more than several days
  • Gas, bloating or cramps in the bowel or rectum
  • A feeling of fullness in the bowel even after a bowel movement
  • A pain or lump in the rectum or bowel

Other symptoms may include fatigue, weakness and unintended weight loss.

Many of the symptoms related to bowel cancer can also be caused by other illnesses, such as irritable bowel syndrome. Certain medications and foods can also cause some of these symptoms. It’s important to discuss any changes or symptoms with a doctor.