Are your stools coming out like flat ribbons and scaring the daylights out of you?

If so, you’ve no doubt read or heard that colon cancer can cause BMs to come out in the shape of flat ribbons.

If this happens what should you do?

When someone notices ribbon stools, “the medical provider is concerned about the possibility of colon obstruction or IBS,” says Franjo Vladic, MD, a board certified gastroenterologist with Center for Digestive Health and Endoscopy Center in Ohio.

Dr. Vladic continues, “If there is an obstruction, it’s because there is something in the lumen [lining] of the colon causing it to be thin (i.e., a large colon polyp, narrowing from stricture, or mass).”

Yes, a benign polyp can cause flat ribbon stools by partially blocking the anal exit that BMs would go through, causing the feces to take on this peculiar formation.

A polyp has a good chance of evolving into colon cancer if not removed, so that’s why during a colonoscopy, any polyps that are discovered are removed on the spot — as shown below in the illustration.

Schematic of polyp removal inside the colon. Shutterstock/Phonlamai Photo

A “mass” can be cancer in the colon—which would be discovered in a colonoscopy, removed and sent to a pathology lab for a confirmation biopsy.

“For IBS, stools can be flat, but providers are unaware as to what causes the stool to present this way,” says Dr. Vladic.

Bottom line: If you notice your stools are in the shape of flat ribbons, see a doctor. Do not make assumptions.

Other Symptoms of Colon Cancer

(No particular order)

Abdominal pain

Unexplained diarrhea

Unexplained constipation

Blood in your stools. This can appear as red clots, maroon clots or like a black tarry or gooey substance.

Unexplained weight loss

Feeling you have to have a bowel movement even though you just had one.

Fatigue or weakness for no reason

Cologuard for Colon Cancer Screening


A test called Cologuard can be taken at home if you’re worried about colon cancer or have flat ribbon stools.

It works as follows: A sample of your bowel movement is sent out for analysis with state-of-the-art DNA technology that will detect abnormal cells that are suspicious for colon cancer.

Your doctor can then advise you on undergoing a colonoscopy.

Another Suspicious Symptom

When constipation alternates with diarrhea, you should inform your doctor.

Here is exactly what “constipation alternating with diarrhea” means.

More information on Cologuard

Dr. Vladic’s special interests include acid reflux, colitis, colon cancer, GERD, heartburn, IBS, liver disease, obesity, pancreatitis and peptic ulcer, among many others.
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.  

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