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