Can flat or ribbon shaped stools differ in appearance from between hemorrhoids and colon cancer? Are there other distinguishing metrics?

Colon cancer can cause bowel movements to come out flat or ribbon shaped. But so can hemorrhoids.

What should you do if you begin seeing flat or ribbon-like poops when you’ve been diagnosed previously with hemorrhoids?

This question is especially vexing if you have no other symptoms that are caused by colon cancer such as visible blood in your BMs, constipation, abdominal pain and unexplained fatigue.

“Whatever lesion is constricting the lowest part of the passageway can imprint the final shape of the stool,” says Joseph Weiss, MD, board certified gastroenterologist and clinical professor of medicine at the Medical School, University of California, San Diego.

“Cancer of the rectum typically continues to progressively narrow the caliber of the stool to pencil diameter before it completely obstructs the passage.

“Benign strictures and scarring from previous surgery, inflammation, radiation, anal cancer, large anal warts, hemorrhoids and scar tissue from anorectal surgery can lead to misshapen and flattened ribbon-like stool.

“The change in shape by itself cannot identify if the source is benign or malignant.

“That change in shape is an alarm warning that an internal examination is warranted.

“Even the gloved finger of an experienced proctologist or gastroenterologist cannot definitively determine the nature of a lesion by palpation.”

It’s impossible to tell the difference, either by staring into the toilet bowl or by examining your poops on a paper plate under a bright light, if the flat or ribbon shape was caused by colon cancer or your hemorrhoids.

Even a physician can’t tell by just looking at the shape.

False Sense of Security

Dr. Weiss explains, “The presence of known prolapsed hemorrhoids may give the false sense of assurance that the cause is benign.

“The presence of hemorrhoids does not reduce the risk of colorectal or anal cancer, and may increase the risk by delaying diagnosis with the incorrect presumption that the hemorrhoids are the source of stool shape change, blood, mucus, etc.

“While going to the doctor for an anorectal examination or procedure is not a favorite activity, delaying and suffering the consequences of advanced cancer is a tragedy that could and should be avoided.

“The American Cancer Society had a pointed message about screening and examinations for colorectal cancer: Don’t die of embarrassment!

Dr. Weiss is the author of Got Guts! A Guide to Prevent and Beat Colon Cancer. He has also presented numerous presentations on various health topics.
Lorra Garrick has been covering medical, fitness and cybersecurity topics for many years, having written thousands of articles for print magazines and websites, including as a ghostwriter. She’s also a former ACE-certified personal trainer.  


Top image: NCI