But it’s not colon cancer that can make bowel movements yellow and foamy looking.

It’s another kind – one with a 5 year survival rate of only 19 percent.

“If you’ve ever looked at your stool and found it to be a slightly different color, it very well could be from the food you ate,” says Benjamin Levy, MD, board certified gastroenterologist who provides clinical care to patients at Mount Sinai Hospital, Schwab Rehabilitation Hospital, and Sinai Medical Group Touhy Refugee Clinic.

Dr. Levy explains, “Certain foods such as carrots, sweet potatoes and others that contain food coloring (such as baked goods) can cause stools to be yellowish in color, but there are other reasons to consider.

“For example, diets high in fat can cause loose yellow stools. Binge drinking can do the same.”

When poops are loose, they can have a foamy, scruffy or furry appearance.

Pancreatic Cancer Can Turn Stools Yellow

“Pancreatic cancer and chronic pancreatitis (seen in some alcoholics and patients with autoimmune pancreatitis) can both cause yellow greasy stools that float,” says Dr. Levy.

They float because they contain a lot of fat. There may, or may not be, what appears to be oil slicks on the surface of the toilet water.

“When the pancreas doesn’t produce enough digestive enzymes, the fat content of stool increases and stool can float.”

But not all causes of floating fatty poops are sinister. If brown poops float, the cause may be inflammatory bowel disease.

Dr. Levy continues, “Because recurring changes in stool color can be an early warning sign of pancreatic cancer, I recommend seeking medical attention if this is a concern.”

The five year survival rate of this disease is a dismal 19 percent because usually, it is diagnosed at a later stage.

“If a pancreatic cancer grows large enough to cause a bile duct obstruction, the stool can also turn pale.” This pale color may be grey or beige.


Dr. Levy explains, “Lastly, giardia is a type of parasitic infection (sometimes caused by drinking untreated water from a stream or lake, or from oral-anal sex) that can cause foul-smelling diarrhea that is sometimes yellow, along with stomach cramps, nausea and sometimes a mild fever. Physicians can evaluate for giardia by ordering stool samples.”

Other Causes of Yellow Stool — but not Necessarily Loose

Dr. Levy’s research and clinical projects have focused on health care disparities, GERD, the early detection of pancreatic cancer and the development of colon cancer screening campaigns.
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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