How stools may change with different stages of colon cancer

Stage 0 and stage 1 colon cancer

In the early stages of colon cancer, the cancer is smaller and hasn't spread outside the colon. Most people likely won't notice any difference in their stools. There may be a small bit of blood in the stool that's hard to see.

Stage 2 colon cancer

In stage 2, the colon cancer has spread into the outermost layers of the colon and possibly nearby tissues or organs. You may notice:

• Visible blood in your stools.
• Stools that start to look thinner.
• Going to the bathroom more often or feeling like you can't finish.

Stage 3 colon cancer

In stage 3, the colon cancer has grown bigger and has spread into nearby lymph nodes. You may notice:

• Pencil-thin stools happen more often.
• Diarrhea or constipation won't go away.
• More blood and mucus in the stools.

Stage 4 colon cancer

In stage 4, colon cancer has spread to other parts of the body. This is called metastatic or distant colon cancer. At this stage, the colon might be blocked or not function well. You may notice:

• Stools may be very thin or may look like pellets. Or you might not be able to pass stools at all.
• Blood in stools is common, and stools can be very dark.
• Severe stomach pain and swelling.