Colorectal cancer can cause many symptoms.
Warning signs to watch for include:
- Change in bowel habits
- Diarrhea or constipation
- Blood in or on the stool (either bright red or very dark in color)
- Stools that are narrower than usual
- General stomach discomfort (bloating, fullness and/or cramps)
- Frequent gas pains
- A feeling that the bowel does not empty completely
- Weight loss with no known reason
- Constant tiredness
People who have any of these symptoms should see their doctor. The doctor may refer them to a doctor who specializes in diagnosing and treating digestive problems (a gastroenterologist).