Rectal Bleeding

Ivor Benjamin, MD
Last Modified: November 1, 2001

Dear OncoLink "Ask the Experts,"
Sometimes after a bowel movement, I notice blood on the tissue paper and a streak of blood along one side of the flat stool. I do plan on returning to see my doctor, but I still do not know the significance of this finding. Could someone please let me know?  
Thank You

Ivor Benjamin, MD, Former Co-Editor-in-Chief of OncoLink, responds:

Dear Paul,
Blood in the stool may be caused by many factors. Some of these are benign (not cancer) such as hemorrhoids, anal fissures (cracks), anal warts, etc. However, it is possible for blood in the stool to be a warning sign for colon, rectal, intestinal, stomach, pancreatic or esophageal cancer. When you can actually see blood streaks on the stool, this implies that the source is close to the anus and hemorrhoids are a common cause for this type of bleeding. When the source of the bleeding is more toward the upper gastrointestinal tract (colon, small bowel, stomach, etc.) the blood is not easily visible in the stool. This situation is called "occult blood in the stool". Fortunately, a simple test of a small stool sample is very sensitive for this and may be performed in your doctor's office.

You also mentioned that your stools had a "flat" appearance. Change in the shape of your stool is also a possible warning sign for cancer because a tumor can partially block the passage of stool from your anus. This could result in a molding of the stool.

You should continue to report any problems to a qualified physician.

Best of luck to you.