What are the symptoms of colorectal cancer?

People with colorectal cancer often don't have symptoms right away. By the time symptoms start, the cancer may have grown or spread to other organs. This can make it harder to treat. This is why routine colorectal cancer screening is important. Screening is designed to help find and even remove precancerous polyps before they become cancer.

Symptoms can include:

• A change in bowel habits that lasts for more than a few days, such as diarrhea, constipation, or a feeling that your bowel is not empty after a bowel movement.

• Bright red or very dark blood in your stool.

• Constant tiredness.

• Stools that are thinner than normal, described as "pencil thin" or a different shape than usual.

• Ongoing gas pains, bloating, fullness, or cramps.

• Unexplained weight loss.

• Weakness.

• Change in appetite.

When to see your doctor

These symptoms are also caused by many kinds of common health conditions. A health care provider will need to find out if your symptoms are caused by cancer. Talk with your provider if you have any of the above symptoms.