Narrow stools
This symptom is very important, and it is something patients usually report only when asked because they may not even notice. Colon cancer reduces the space in the intestinal lumen, and that’s where stool passes in its way to be eliminated. The space becomes reduced, and the stools become narrow trying to pass the obstruction. Narrow stools are common in other inflammatory conditions that lead to a reduced intestinal lumen, but it is a useful sign you should report to your doctor if you’re suspecting colon cancer.