Are there signs and symptoms?

Colorectal cancer starts without signs or symptoms. Once cancer has developed some people may have symptoms, such as:

  • Changes in bowel habits
  • Blood in stool (can be dark in color or tar-like)
  • Stomach pain or cramping
  • Unintended weight loss

People who have signs or symptoms should be screened using a different schedule than people who are not experiencing any signs or symptoms. Anyone with symptoms should talk to their doctor.