In early stages, colon cancer may not cause any symptoms. Also, symptoms of colon cancer vary depending on the location and size of the cancerous polyps. Some early warning signs and symptoms of colon cancer in both, men and women are:
A noticeable change in bowel habits, (constipation or diarrhoea) for more than four weeks with or without changes in stool consistency (hard or watery stools)
Any kind of bleeding from the rectum (anus), or blood-stained stools
Persistent discomfort in the abdomen and symptoms like gas, cramps, or pain
Persistent feeling of incomplete emptying of bowels
Fatigue or weakness
Unexplained weight loss